L-778123 is an inhibitor of FPTase and GGPTase-I with IC50 of 2 nM and 98 nM in enzyme inhibition determination. IC50 value: 2 nM [1] Target: FPTase in vitro: L-778123 can completely inhibit Ki-Ras prenylation. [1] L-778123 as a farnesyltransferase inhibitor can have a good cytotoxic activity as a classic anti-cancer agent. [2] in vivo: In the dog model, L-778123 inhibits HDJ2 prenylation and produces measurable, albeit slight (5%), levels of unprenylated Rap1A in PBMCs. [1]