They are mainly used in the treatment of melanoma, but the efficacy of single-agent therapy for mCRCs remains unclear [68], which is mainly related to the fact that, after inhibiting the MAPK pathway using BRAF inhibitors, EGFR can be activated by feedback in mCRCs, whereas melanoma only expresses low-level EGFR [69, 70]. The gene discussed is EGFR; the disease is melanoma.