CDKN1B and melanoma: Additionally, since in our previous study we observed the induction of p27kip1 in melanoma cells treated with PLX4032 (24) and based on the observation that LM16 cells exposed to the combination of KP54/PLX4032 improve the PLX4032-mediated induction of p27kip1 (Supplementary Figure 4), we sought to investigate whether KP54 exposure perturbes the cell-cycle.