19. Subordination and Nondisturbance. Tenants interest in this Lease shall be subject and subordinate in all respects to any fee owner, ground or prime lease (including, without limitation, any Over-Lease or master lease agreement resulting from a sale by Landlord of its interest in the Property to a third party and a lease-back of the entire Property by Landlord from such third party) or the lien of any mortgage or deed of trust which may now or hereafter be placed on the Property. Upon Tenants request, Landlord shall request and use commercially reasonable efforts to obtain from any present or future mortgagee, trustee, fee owner, ground or prime lessor, or any person having an interest in the Premises superior to this Lease (a Superior Interest) a written subordination and nondisturbance agreement in recordable form, providing that so long as Tenant performs all of the terms, covenants and conditions of this Lease and agrees to attorn to the mortgagee, beneficiary of the deed of trust, purchaser at a foreclosure sale, ground or prime lessor or fee owner, Tenants rights under this Lease shall not be disturbed and shall remain in full force and effect for the Term, and Tenant shall not be joined by the holder of any mortgage or deed of trust in any action or proceeding to foreclose thereunder, unless such joinder is required for jurisdictional purposes. Landlord shall not have any liability to Tenant if it is not able to obtain such subordination and nondisturbance agreement.