Item 2. PROPERTIES

We conduct our research, development, manufacturing, and administrative activities at our owned and leased facilities. A summary of our significant owned and leased properties is provided below.

Tarrytown, New York

At our Tarrytown, New York location, we lease approximately 1,467,000 square feet of laboratory and office space, of which approximately 1,354,000 square feet is occupied by Regeneron. Refer to Part II, Item 7. "Management's Discussion and Analysis of Financial Condition and Results of Operations - Liquidity and Capital Resources - Tarrytown, New York Leases" for further details. We also own an approximate 100-acre parcel of undeveloped land adjacent to our Tarrytown, New York location, which we plan to start developing in 2022, primarily in connection with expanding our research and support facilities to accommodate our growth.

Rensselaer, New York

We own facilities in Rensselaer, New York totaling approximately 950,000 square feet of manufacturing, research, office, and warehouse space. This includes approximately 212,000 square feet of warehouse space which we constructed on a 130-acre parcel of land near our Rensselaer facility. We are in the process of further developing this property, primarily in connection with constructing a fill/finish facility.

Limerick, Ireland

We own a facility in Limerick, Ireland totaling approximately 555,000 square feet of manufacturing, warehouse, laboratory, and office space. We are in the process of further developing this property to support our growth and expand our manufacturing capacity.