PPIB and cutaneous melanoma: BRAF mutations are found in 40% to 60% of cutaneous melanomas, and the replacement of valine with glutamic acid at codon 600 (B-RafV600E) accounts for approximately 90% of these mutations.[48] The small-molecule kinase inhibitor vemurafenib (Vem) exhibits a selective targeting mechanism, specifically inhibiting the active form of B-RafV600E, and was approved by the FDA in 2011.[48] However, acquired resistance presents a major barrier to its clinical use.