For example, neoantigen-reactive T cells have been found to express a high amount of PD-1 following neoantigen vaccines.496–498 In a study conducted by Patrick A. Ott et al., vaccination with neoantigens was associated with neoantigen-specific T cell expansion and induction of polyfunctional CD4+ and CD8+ T cells, which targeted 58 out of 97 unique neoantigens in melanoma patients. Here, PDCD1 is linked to melanoma.