KLRC1 and neoplasm: On the other hand, CD8+ T cell and NK cell interaction, the expression levels of NKG2A in tumor-infiltrating tissues and peripheral blood were similar for NK cells, CD8 T cells showed a large difference in expression levels of NKG2A in tumor-infiltrating tissues and peripheral blood, where NKG2A is a constant companion, CD8+ T cells play a game of hide-and-seek with this inhibitory receptor.