To further confirm the role of tumor antigens in driving NKG2A/CD94 expression of tumor‐specific CD8+ T cells, anti‐CD3/anti‐CD28‐activated P14 cells (CD45.1+CD45.2−) and OT1 cells (CD45.1+CD45.2+) were co‐transferred into C57BL/6 recipients (CD45.1−CD45.2+) engrafted with B16F10‐GP or B16F10‐OVA or B16F10 (Figure 3C). This evidence concerns the gene CD28 and neoplasm.