Western blot analysis showed a reduction of MAPK kinase signaling pathway after exposure to dabrafenib in BrafV637E tumor cells but not in control p53-null NSCs or PDGFB tumorspheres (Fig. 7e), thus confirming the dependency on BRAF activation for the maintenance of MEK/ERK signaling in BrafV637E tumors. The gene discussed is PDGFB; the disease is neoplasm.