The proportion of patients from the BRAF inhibitor alone treatment group who had a high-grade CAEs compared with the BRAF and MEK inhibitor treatment group were 29.02% vs. 4.98% for palmoplantar erythrodysaesthesia syndrome and 19.86% vs. 6.98% for palmoplantar keratoderma. Here, MAP2K7 is linked to hereditary palmoplantar keratoderma.