THY1 and neoplasm: In light of the finding of CRC-associated tr-NK and non-tr-NK cells expressing PD-1 and/or KIRs and NKG2A, we analyzed the surface expression of their respective ligands, PD-Ls and HLA-I molecules, on tumor cells derived from CRC samples (identified as CD45– EpCAM+ CD90– cells, Supplementary Figure 1B), to evaluate whether those critical ICs might play a role in regulating NK cell-mediated antitumor responses against CRC.