RALA and viral infectious disease: Among the inhibitors of small GTPases tested [26,27], a Cdc42 inhibitor (ZCL278) reduced viral infection to target cells in MT-2-based co-culture (Fig 4B, upper), whereas a Ral inhibitor (BQU57) reduced viral infection in both MT-2- and SLB-1-based co-cultures (Fig 4B).