CD4 and neoplasm: It has been shown that the tumor microenvironment plays a central role in tumorigenesis development and progression, and the levels of tumor-infiltrating CD4+/CD8+ T cells, M1 macrophages, NK cells, and inflammatory cytokines directly influence the onset of immune priming and adaptive immunity (Topalian et al., 2016; Galon and Bruni, 2019; Zeng et al., 2020).