In conclusion, therapy with BRAF and MEK inhibitors was associated with an decreased risk of CAEs, especially rash, alopecia, hyperkeratosis, palmoplantar erythrodysaesthesia syndrome, palmoplantar keratoderma, skin papilloma, cutaneous squamous-cell carcinoma, and keratoacanthoma, compared with BRAF inhibitor monotherapy. The gene discussed is MAP2K7; the disease is hereditary palmoplantar keratoderma.