While the majority of apoptosis signature genes showed similar expression levels at baseline between MEKi-sensitive and MEKi-resistant melanoma cell lines, a few genes were found to be elevated in sensitive lines, including UBE4B, Ankyrin-2 (ANK2), tripartite motif-containing protein 2 (TRIM2), enhancer of polycomb homolog 2 (EPC2), and rap guanine nucleotide exchange factor 2 (RAPGEF2). This evidence concerns the gene RAPGEF2 and melanoma.