CD4 and neoplasm: Specifically, MHC class I molecules, such as HLA-A, interact with CD8+ T cells to facilitate tumor cell destruction, while MHC class II molecules—HLA-DPA1, HLA-DPB1, HLA-DQA1, HLA-DQB1, and HLA-DRB1—are predominantly expressed on antigen-presenting cells, such as dendritic cells and macrophages, where they are recognized by CD4+ T cells [57].