Lactate in the TME also boosts CD8+ T cell stemness and anti-tumor immunity (56), while gut microbiota-derived butyrate enhances chemotherapy efficacy by modulating CD8+ T cell function (57), and indole-3-carboxylic acid (ICA) augments CD8+ T cell functionality by inhibiting regulatory T cell differentiation (58). Here, CD8A is linked to neoplasm.