PLX4032 is an orally bioavailable, ATP-competitive inhibitor of mutant V600E and wild type B-Raf kinases (IC50s = 31 and 100 nM, respectively). It inhibits cell proliferation in a variety of cell lines expressing B-Raf V600E and synergizes strongly with taxol, vinblastine, and oxaliplatin in inhibiting the proliferation of B-RafV600E transformed cancer cells. PLX4032 is effective against the growth of tumors bearing the B-Raf V600E mutation.