For example, previous studies have reported that CD4+ T cells can secrete IL-1, IL-6, IFN-γ, and other cytokines in TME, thereby activating other immune cells to eliminate the intracellular pathogens and tumor cells, but the immunity of CD4+ T cells is usually suppressed by CRC cells via activating the Wnt signaling pathway (Lin et al., 2020; Sun et al., 2017). Here, IL6 is linked to neoplasm.