PDCD1 and melanoma: In a retrospective study of patients with melanoma who received programmed cell death 1 (PD-1) inhibitor and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor therapy, there was an increase in systolic blood pressure when the use of anti-hypertensive agents and increased pain were controlled.26 Further studies will be needed to confirm this potential for an increased incidence of hypertension following treatment with IO therapy.