FOURTH AMENDMENT TO LEASE EXHIBIT 10.20 This Fourth Amendment to Lease (this "Amendment") is made by and between VICAL Incorporated, a Delaware Corporation ("Tenant"), and Nippon Landic (U.S.A.), Inc., a Delaware Corporation ("Landlord"), with...Lease • November 15th, 1999 • Vical Inc • Biological products, (no disgnostic substances)
