Figure 5.

m⁶A modification is involved in formation of immune escape or immune suppression

Immunosuppressive cells and cytokines that facilitate immune escape in TME mainly include TAMs, Tregs, MDSCs, CAFs, DCregs, and Bregs, and immunosuppressive cytokines comprise IL-10, TGF-β, IL-17, Th17, tumor-derived exosomes, and immune checkpoint molecule, such as PD-1, CTLA-4, and TIGIT, among others. The m6A score is associated with activation of immunity and PD-1 expression levels to different degrees in various cancers. FTO promotes the expression of immune checkpoint molecules, such as PD-1L and LILRB4. YTHDF1 destructs neoantigen-specific immunity through mediating m6A modification of transcripts that encode lysosomal proteases to promote immune escape. In addition, YTHDF2 isolates m⁶A-circRNA and acts as an essential factor for suppression of innate immunity.