Additionally, SCFAs have been reported to bind to the GPR43 in the gastrointestinal tract, triggering a series of antitumor immune responses on colorectal tumor-bearing mice, markedly increasing the frequency of CD8+, IFN-γ+CD8+, and CD4+ T cells within the tumor tissues, activating dendritic cells (DCs) (CD86+CD11c+), promoting M1 polarization of macrophages, and reducing the frequency of myeloid-derived suppressor cells (MDSCs) (Fig. 8A) [32,70]. The gene discussed is CD4; the disease is neoplasm.