IL6 and cancer: Accumulation of cancer cell-derived lactate in the TME has been shown to impair cytotoxic T-lymphocyte cytokine production and proliferation by blocking and disrupting T-cell metabolism via lactate efflux and lactate from cancer cells stimulates production of IL-6 by cancer-associated fibroblasts (CAFs), synergistically impairing cytotoxic lymphocyte function (10).However, it has been found that lactate-pretreated in vitro CD8 + T cells effectively inhibit tumor growth when overtransferred to hormonal mice, and that lactate increases stemness and enhances anti-tumor immunity in CD8 + T cells.