Whole-exome sequencing of DMBC21, 21_TRAR, and 21_PLXR cells revealed no mutations in the key components of the WNT/β-catenin signaling pathway; however, mutations present in 21_PLXR cells in key melanoma genes such as CDKN2A, DUSP6, ERBB2, or E2F3 might impact the resistance of vemurafenib-resistant cell lines to PRI-724 treatment (Supplementary Table S1). This evidence concerns the gene E2F3 and melanoma.