Subsequent Events	6 Months Ended
Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	14. Subsequent Events In July 2019, we entered into an Office Sublease (the “Powell Street Sublease”) for office space located at 2100 Powell Street, Emeryville, California (the “Powell Street Premises”). The purpose of the Powell Street Sublease is to replace our current leased premises at 2929 Seventh Street, Berkeley, California. We moved our corporate headquarters to the Powell Street Premises on July 29, 2019. Under the terms of the Powell Street Sublease, we are leasing 23,976 square feet in the Powell Street Premises at the rate of $3.90 per square foot, paid on a monthly basis. Rent is subject to scheduled annual increases and we are responsible for certain operating expenses and taxes throughout the life of the Powell Street Sublease. The Powell Street Sublease will continue until June 30, 2022. Also in July 2019, we entered into a Sublease (the “Horton Street Sublease”) to sublease the entire office/laboratory space located at 5959 Horton Street, Emeryville, California (“Horton Street Premises”). We had previously agreed to lease the Horton Street Premises as our new corporate headquarters (“Horton Street Master Lease”). See Note 6. We have not occupied and do not intend to occupy any of the Horton Street Premises. Under the terms of the Horton Street Sublease, we are subleasing all of the Horton Street Premises consisting of 75,662 rentable square feet at the rate of $5.50 per square foot, paid on a monthly basis. Rent is subject to scheduled annual increases and the subtenant is responsible for certain operating expenses and taxes throughout the life of the Horton Street Sublease. The Horton Street Sublease will continue until March 31, 2031, concurrent with the term of our Horton Street Master Lease.

Subsequent Events

6 Months Ended

Jun. 30, 2019

14. Subsequent Events

In July 2019, we entered into an Office Sublease (the “Powell Street Sublease”) for office space located at 2100 Powell Street, Emeryville, California (the “Powell Street Premises”). The purpose of the Powell Street Sublease is to replace our current leased premises at 2929 Seventh Street, Berkeley, California. We moved our corporate headquarters to the Powell Street Premises on July 29, 2019.

Under the terms of the Powell Street Sublease, we are leasing 23,976 square feet in the Powell Street Premises at the rate of $3.90 per square foot, paid on a monthly basis. Rent is subject to scheduled annual increases and we are responsible for certain operating expenses and taxes throughout the life of the Powell Street Sublease. The Powell Street Sublease will continue until June 30, 2022.

Also in July 2019, we entered into a Sublease (the “Horton Street Sublease”) to sublease the entire office/laboratory space located at 5959 Horton Street, Emeryville, California (“Horton Street Premises”). We had previously agreed to lease the Horton Street Premises as our new corporate headquarters (“Horton Street Master Lease”). See Note 6. We have not occupied and do not intend to occupy any of the Horton Street Premises.

Under the terms of the Horton Street Sublease, we are subleasing all of the Horton Street Premises consisting of 75,662 rentable square feet at the rate of $5.50 per square foot, paid on a monthly basis. Rent is subject to scheduled annual increases and the subtenant is responsible for certain operating expenses and taxes throughout the life of the Horton Street Sublease. The Horton Street Sublease will continue until March 31, 2031, concurrent with the term of our Horton Street Master Lease.