Nivolumab, an anti-programmed cell death-1 (PD-1) antibody, is approved in the United States and other countries as adjuvant therapy for resected stage III or IV melanoma based on evidence from the phase 3 CheckMate 238 randomized controlled trial (RCT), which included patients with in-transit metastasis with and without nodal involvement [2]. Here, PDCD1 is linked to melanoma.