To date, monotherapies using small-molecule inhibitors of BRAF V600E (e.g., vemurafenib and dabrafenib) have been approved for clinical use in patients with inoperable and metastatic melanoma, followed by the introduction of the BRAF/MEK (mitogen-activated protein kinase kinase) combination treatment, owing to the quickly emerging resistance based on the reactivation of the mitogen-activated protein kinase (MAPK) pathway in patients treated with single-agent therapy [7,8]. The gene discussed is WNK2; the disease is metastatic melanoma.