(I) Validation of SMAD3 knock-down by western-blot experiments in Me1402 cells exposed or not to vemurafenib (BRAFi (Vem) 5µM, 2 days). Cells were exposed to BRAFi 24hr after siRNA transfection. Vemurafenib inhibitory effect on mutated BRAF was evaluated by analysing the phospho-ERK1/2 levels. ERK and HSC70 serves as loading control. 