To better characterize the effect of NS1643 on melanoma cell proliferation we monitored the expression level of proteins that are traditionally known to promote proliferation by regulating progression through the different phases of the cell cycle including cyclin E that is important for promoting G0/G1 to S phase transition, cyclin D that is important for progression through the S phase, cyclin B and Wee1 that are important for promoting S to G2/M transition. This evidence concerns the gene WEE1 and melanoma.