There is still no precise information about what happens to circulatory CD8+ T cells.[54, 78] A study showed that the intratumoral expression of PD‐1 could be useful as a biomarker in identifying resident neoantigens‐specific CD8+ T cells in tumor tissue.[79] This study showed that despite the low frequency of CD8+ PD‐1+ cells, these cells could identify neoantigens in the circulation of patients with melanoma cancer. This evidence concerns the gene CD8A and neoplasm.