Antitumor activity of PD in melanosphere-derived subcutaneous xenografts. Growth curves of xenografts derived from mutant-BRAF (A) or wild type-BRAF (C) melanospheres in control or PD0325901-treated mice. Mean ± SD of 3 independent experiments is shown. *** p < 0,001. B-D) Immunohistochemistry for KI-67, p-Erk and mouse CD34 in control or treated BRAF-mutated (B) or BRAF-wild type (D) xenografts. E) Immunoblot for VEGF expression in control or PD0325901-treated representative melanospheres with mutated- or wild type-BRAF. F) Immunohistochemistry for VEGF in control or PD0325901-treated xenografts.