However, long-term survival rates for patients with metastatic disease are improving with the incorporation of novel treatment options [4, 5], such as BRAF- and MEK-targeted therapies, intratumoral oncolytic herpes viral therapies, and immune checkpoint inhibitors (ICIs) targeting cytotoxic T-lymphocyte associated–protein 4 (CTLA-4) and programmed cell death-1 (PD-1) [6]. Here, PDCD1 is linked to metastatic neoplasm.