Base Rent. Commencing on the Base Rent Commencement Date and continuing throughout the Term of this Lease, Tenant shall pay to Landlord and Landlord shall receive, without notice or demand Base Rent as specified in the Basic Lease Information, payable in monthly installments in advance on or before the first day of each calendar month, in lawful money of the United States, without deduction or offset whatsoever, at the Landlord’s Rent Remittance Address specified in the Basic Lease Information or to such other place as Landlord may from time to time designate in writing. At Landlord’s election, and upon written notice to Tenant, all payments required to be made by Tenant to Landlord hereunder (or to such other party as Landlord may from time to time specify in writing) shall be made by Electronic Fund Transfer of immediately available federal funds before 11:00 a.m., Eastern Time, at such place, within the continental United States, as Landlord may from time to time designate to Tenant in writing. Base Rent for the first full month due on the Base Rent Commencement Date shall be paid by Tenant upon Tenant’s execution of this Lease. If the obligation for payment of Base Rent commences on a day other than the first day of a month, then Base Rent shall be prorated and the prorated installment shall be paid on the first day of the calendar month next succeeding the Base Rent Commencement Date. The Base Rent payable by Tenant hereunder is subject to adjustment as provided elsewhere in this Lease, as applicable. As used herein, the term “Base Rent” shall mean the Base Rent specified in the Basic Lease Information as it may be so adjusted from time to time. The obligation of Tenant to pay Base Rent and other sums to Landlord and the obligations of Landlord under this Lease are independent obligations.

Additional Rent. All monies other than Base Rent required to be paid by Tenant hereunder, including, but not limited to, Tenant’s Proportionate Share of Operating Expenses, as specified in Paragraph 7 of this Lease, charges to be paid by Tenant under Paragraph 15, the interest and late charge described in Paragraphs 26.4 and 26.5, and any monies spent by Landlord pursuant to Paragraph 30, shall be considered additional rent (“Additional Rent”). Except as otherwise provided herein, all items of Additional Rent shall be paid within 30 days after Landlord’s request for payment. “Rent” shall mean Base Rent and Additional Rent.

Rent Abatement. If Landlord or Tenant does not elect to terminate this Lease under Paragraph 25.3 or Paragraph 25.4, this Lease shall remain in full force and effect provided that Tenant shall be entitled to a reduction of Base Rent and Tenant’s Proportionate Share of Operating Expenses in proportion that the areas of the Premises rendered untenantable bears to the total rentable area of the Premises during the period beginning with the date such rentable area becomes untenantable and Tenant ceases to use such rentable area for the normal conduct of its business and ending five (5) Business Days after Substantial Completion of Landlord’s Restoration Work. For purposes of this Paragraph 25, the term “Substantial Completion” or “Substantially Complete” shall have the same meaning as provided in the Tenant Improvement Agreement with respect to Substantial Completion of the Base Building Improvements.

Base Rent. The Base Rent for the Premises will be abated as of the Commencement Date, and Tenant will pay rent for the Suite 500 Premises beginning on the Commencement Date.

Base Rent. From and after the Expansion Date, Base Rent with respect to the Premises, including the Expansion Space, shall be as follows:

Base Rent. In addition to the Base Rent payable pursuant to [Section 5.1(a)] of the Lease and all other Rent payable thereunder, Tenant shall pay Base Rent for the Expansion Space in accordance with the following table:

Rent Roll. A current rent roll (“Rent Roll”) for each of the Properties;

Base Rent. Notwithstanding anything to the contrary in the Lease, during the Extended Term, Tenant shall pay, in accordance with the provisions of this Section 5, Monthly Base Rent for the New Premises as follows:

Fair Market Value. For purposes of any ISO granted hereunder (or, if applicable, related Stock Appreciation Right), the Fair Market Value of Shares shall be determined in the manner required by Section 422 of the Code and any Treasury regulations thereunder.

Prevailing Market Rate. The Base Rent payable by Tenant for the Premises during an Extension Term shall be the Prevailing Market Rate (as defined below) for the Premises, valued as of the commencement of such Extension Term, determined in the manner hereinafter provided. As used herein, the term “Prevailing Market Rate” shall mean the annual Base Rent that a willing tenant would pay, and that a willing landlord would accept, at arm’s length, for space comparable to the Premises within other comparable first class office buildings having more than two (2) stories located in the area including and bounded by South San Francisco to the north and Sunnyvale to the south (the “Comparable Buildings”), based upon binding lease transactions for tenants in Comparable Buildings (“Comparable Leases”). Comparable Leases shall include renewal and new non-renewal tenancies, but shall exclude subleases and leases of space subject to another tenant’s expansion rights. Rent rates payable under Comparable Leases shall be adjusted to account for variations between this Lease and the Comparable Leases with respect to: # the length of the Extension Term compared to the lease term of the Comparable Leases; # the rental structure, including, without limitation, rental rates per rentable square foot (including whether gross or net, and if gross, adjusting for base year or expense stop), additional rental, all other payments and escalations; # the size of the Premises compared to the size of the premises of the Comparable Leases; # the location, floor levels and efficiencies of the floor(s) of the Premises compared to the premises of the Comparable Lease; # free rent, moving expenses and other cash payments, allowances or other monetary concessions affecting the rental rate; # the age and quality of construction of the Building compared to the Comparable Building; # the leasehold improvements and/or allowances, including the amounts thereof in renewal leases, and taking into account, in the case of renewal leases (including this Lease), the value of existing leasehold improvements to the renewal tenant, # access and proximity to Caltrain, # the amenities available to tenants in the Building compared to amenities available to tenants in Comparable Buildings; # the energy efficiencies and environmental elements of the Building compared to Comparable Buildings, including improvements required for the U.S. Green Building Council’s Leadership in Energy and Environmental Design (“LEED”) certification, # the brokerage commissions, # the availability of parking, the parking ratio and parking charges, and # the relative market rent rates within the geographic area referenced in the definition of Comparable Buildings.