KLRC1 and neoplasm: NKG2A is suggested as the “culprit” of the adaptive tolerance of CD8+ T cells to cancer vaccines.[77] The upregulation of siglec‐15, an important immunosuppressive factor, was detected in tumor cells, myeloid cells, and M2‐like macrophages in the TME and was mutually exclusive with PD‐L1 expression, which may be related to some cytokines such as M‐CSF and IFN‐γ.