MRC1 and neoplasm: After further stratifying CD206+ TAMs as HLA-DRhigh and HLA-DRlow/− subgroups, we found a correlation of cell number and colocalization of HLA-DRhigh CD206+ TAMs with CD4+ tumor-infiltrating T lymphocytes in LSCC, which strongly suggest that the CD4+ T cell/MHC-II axis plays a key role in the cross-talk of tumor-infiltrating macrophage and T lymphocytes in the TME of LSCC.