Baseline genetic characteristics of BRAF V600-mutated metastatic melanoma patients treated with cobimetinib plus vemurafenib or vemurafenib alone showed that MITF and TP53 alterations were more frequent in patients who progressed rapidly, while NF1 alterations were more frequent in patients who obtained a complete response, which is consistent with the view that melanomas that lack NF1 expression are more dependent on the MAPK signaling pathway and are more sensitive to MAPK pathway inhibitors. The gene discussed is NF1; the disease is melanoma.