Icatolimab (JS004, TAB004) is a novel anti-BTLA mAb currently under investigation for patients with advanced solid malignancies, including melanoma, refractory to standard therapies in two phase-I trials, as monotherapy or in combination with PD-1 inhibition (NCT04137900 and NCT04773951, respectively). The gene discussed is PDCD1; the disease is melanoma.