The phase 1 Lipo-MERIT Trial (NCT02410733) aimed to evaluate the efficacy and safety of a tetravalent RNA vaccine (targeting the tumor antigens NY-ESO-1, MAGE-A3, tyrosinase, and TPTE) with or without PD-1 blockade in metastatic melanoma.154 Partial responses were observed in both vaccine monotherapy (12%) and vaccine plus anti-PD-1 treatment (35.3%). The gene discussed is PDCD1; the disease is metastatic melanoma.