CTLA4 and neoplasm: Both HLA-DRA and HLA-DRB1 were underexpressed in NSCLC PBL T cells and overexpressed in NSCLC tumor C11 [49]/C6-LAYN [73] CD8 T cell clusters, C14 CD4/CD8 T-cell clusters [49], and suppressive tumor Tregs of CD4-C9-CTLA4 cells vs. other tumor-infiltrating Tregs of CD4-C8-FOXP3 cells [73].