RPS6KB1 and melanoma: Proteins that integrate ERK and AKT signaling such as p-p70S6K(Thr421/Ser424) kinase and pS6(Ser235/236), known to be important in melanoma (Corcoran et al, 2013), were down-regulated soon after exposure of some cell lines to drug and only much later in others (compare pS6 levels in C32 and WM115 cells exposed to PLX4720; Fig4D).