Trametinib (Mekinist ®) is an orally bioavailable, highly selective and reversible allosteric inhibitor of MEK1/2 [1, 2]. Trametinib is currently approved for monotherapy and in combination with dabrafenib for the treatment of patients with unresectable/metastatic melanoma harbouring BRAF V600 mutation. The gene discussed is BRAF; the disease is metastatic melanoma.