PDCD1 and melanoma: Oulu University Hospital retrospectively collected all patients who had been treated with anti-PD-1 therapy for metastatic disease in lung and genitourinary (renal and bladder) cancers as well as melanoma, with maximal anti-PD-1 therapy length restricted to 6 months, turning out 11 of 17 responders who discontinued anti-PD-1 therapy after 6 months therapy remained SD after 1 year (53).