Related Party Transactions	12 Months Ended
Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions	9. Related Party Transactions In 2011, the Company executed an operating lease for its corporate offices with S Real Estate Holdings LLC. S Real Estate Holdings LLC is owned by Dr. Russell Kern, the Company’s Executive Vice President and Chief Scientific Officer. The lease agreement was negotiated at arm’s length and was reviewed by the Company’s outside legal counsel. The terms of the lease were reviewed by a committee of independent directors, and the Company believes that, in total, those terms are at least as favorable to the Company as could be obtained for comparable facilities from an unaffiliated party. In March 2017, the Company signed an amendment to the lease agreement to extend the term of the lease until 2020 and include annual adjustments to the monthly lease payments. In March 2020, the Company entered into an amendment to the lease agreement. The amendment extended the term of the lease for three years (until February 28, 2023) and provided for a 2% increase in monthly rent. For the years ended December 31, 2021 and 2020, the Company recorded $157 thousand and $169 thousand, respectively, in operating lease cost that was related to the facility lease arrangement with related parties. Between March 6, 2018 and December 17, 2019, to obtain funding for working capital purposes, the Company borrowed a total of $2.3 million from Dr. Semechkin and issued an unsecured, non-convertible promissory note in the principal amount of $2.3 million (the “Note”) to Dr. Semechkin. The outstanding principal amount under the Note accrued interest at a rate of 4.5% per annum. The outstanding principal and accrued interest on the Note was due and payable on January 15, 2021 and could be pre-paid without penalty at any time. On January 15, 2021, the Company and Dr. Semechkin agreed to extend the maturity date of the New Note to January 15, 2022. No other terms of the Note were modified as a result of the extension. On March 5, 2021, to obtain additional funding for working capital purposes, the Company further modified the Note and issued an unsecured, non-convertible promissory note (the “New Note”) in the amount of $2.650 million to Dr. Semechkin. In exchange, Dr. Semechkin surrendered the Note and provided additional funding in the amount of $350 thousand to the Company. The outstanding principal amount under the New Note accrues interest at a rate of 4.5% per annum. The outstanding principal and accrued interest on the New Note is due and payable on January 15, 2022 and may be pre-paid by the Company without penalty at any time. On October 26, 2021, the Company and S Real Estate Holdings, LLC jointly entered into a lease agreement with Rehco Holdings, LLC (the “Lease”), for the purpose of establishing a new corporate headquarters, including corporate, R&D, and manufacturing operations. The Lease was personally guaranteed by the Dr. Russell Kern, the Company’s Executive Vice President and Chief Scientific Officer. On December 15, 2021, the Company and S Real Estate Holdings LLC entered into a co-tenant agreement, whereby the Company and S Real Estate Holdings LLC agreed to allocate portions of the base rent and variable charges, including insurance, maintenance costs, taxes and operating expenses, between the parties. During the term of the Lease, the Company will be liable for 40% of all costs incurred in connection with the Lease, while S Real Estate Holdings LLC will be liable for the remaining 60%. On December 27, 2021, the Company and S Real Estate Holdings LLC mutually agreed to terminate the operating lease for its corporate offices for the purpose of consolidating its operations to its new corporate headquarters (refer to Note 11 – Commitments and Contingencies, for further information). Pursuant to the termination agreement, the Company surrendered the leased premises effective December 31, 2021, and no termination penalties were incurred by the Company. In addition, S Real Estate Holdings LLC released the Company of its obligation to pay base rent for the month of December 2021.

Related Party Transactions

12 Months Ended

Dec. 31, 2021

9. Related Party Transactions

In 2011, the Company executed an operating lease for its corporate offices with S Real Estate Holdings LLC. S Real Estate Holdings LLC is owned by Dr. Russell Kern, the Company’s Executive Vice President and Chief Scientific Officer. The lease agreement was negotiated at arm’s length and was reviewed by the Company’s outside legal counsel. The terms of the lease were reviewed by a committee of independent directors, and the Company believes that, in total, those terms are at least as favorable to the Company as could be obtained for comparable facilities from an unaffiliated party. In March 2017, the Company signed an amendment to the lease agreement to extend the term of the lease until 2020 and include annual adjustments to the monthly lease payments. In March 2020, the Company entered into an amendment to the lease agreement. The amendment extended the term of the lease for three years (until February 28, 2023) and provided for a 2% increase in monthly rent. For the years ended December 31, 2021 and 2020, the Company recorded $157 thousand and $169 thousand, respectively, in operating lease cost that was related to the facility lease arrangement with related parties.

Between March 6, 2018 and December 17, 2019, to obtain funding for working capital purposes, the Company borrowed a total of $2.3 million from Dr. Semechkin and issued an unsecured, non-convertible promissory note in the principal amount of $2.3 million (the “Note”) to Dr. Semechkin. The outstanding principal amount under the Note accrued interest at a rate of 4.5% per annum. The outstanding principal and accrued interest on the Note was due and payable on January 15, 2021 and could be pre-paid without penalty at any time.

On January 15, 2021, the Company and Dr. Semechkin agreed to extend the maturity date of the New Note to January 15, 2022. No other terms of the Note were modified as a result of the extension.

On March 5, 2021, to obtain additional funding for working capital purposes, the Company further modified the Note and issued an unsecured, non-convertible promissory note (the “New Note”) in the amount of $2.650 million to Dr. Semechkin. In exchange, Dr. Semechkin surrendered the Note and provided additional funding in the amount of $350 thousand to the Company. The outstanding principal amount under the New Note accrues interest at a rate of 4.5% per annum. The outstanding principal and accrued interest on the New Note is due and payable on January 15, 2022 and may be pre-paid by the Company without penalty at any time.

On October 26, 2021, the Company and S Real Estate Holdings, LLC jointly entered into a lease agreement with Rehco Holdings, LLC (the “Lease”), for the purpose of establishing a new corporate headquarters, including corporate, R&D, and manufacturing operations. The Lease was personally guaranteed by the Dr. Russell Kern, the Company’s Executive Vice President and Chief Scientific Officer.

On December 15, 2021, the Company and S Real Estate Holdings LLC entered into a co-tenant agreement, whereby the Company and S Real Estate Holdings LLC agreed to allocate portions of the base rent and variable charges, including insurance, maintenance costs, taxes and operating expenses, between the parties. During the term of the Lease, the Company will be liable for 40% of all costs incurred in connection with the Lease, while S Real Estate Holdings LLC will be liable for the remaining 60%.

On December 27, 2021, the Company and S Real Estate Holdings LLC mutually agreed to terminate the operating lease for its corporate offices for the purpose of consolidating its operations to its new corporate headquarters (refer to Note 11 – Commitments and Contingencies, for further information). Pursuant to the termination agreement, the Company surrendered the leased premises effective December 31, 2021, and no termination penalties were incurred by the Company. In addition, S Real Estate Holdings LLC released the Company of its obligation to pay base rent for the month of December 2021.