Comparing with BRAF and MEK inhibitors, treatment with BRAF inhibitors alone was associated with an increased risk of hyperkeratosis (RR, 0.26; 95% CI, 0.08–0.81; p = 0.021; I2 = 0%), palmoplantar erythrodysaesthesia syndrome (RR, 0.09; 95% CI, 0.02–0.57; p = 0.010; I2 = 4%), cutaneous squamous-cell carcinoma (RR, 0.20; 95% CI, 0.11–0.37; P < 0.001; I2 = 33%), and keratoacanthoma (RR, 0.13; 95% CI, 0.04–0.39; P < 0.001; I2 = 0%) (Figure 3). This evidence concerns the gene MAP2K7 and keratoacanthoma.