CD4 and lung adenocarcinoma: Recent studies have shown that after introducing conjugated B-cell- and CD4 T-cell-recognized neoantigens into a lung adenocarcinoma mouse model, B cells induce tumor antigen-specific follicle-assisted CD4+ T cells (TFHs) to secrete IL-21 and promote the production of GzmB by tumor-infiltrating CD8+ T cells 46.