STAT1 and neoplasm: Further studies revealed that miR-21-5p and miR-200a exert effects by regulating the PTEN/AKT and SCOS1/STAT1 pathways within TAMs, thereby synergistically inducing M2 polarization and PD-L1 expression in TAMs and leading to a decrease in the activity of CD8 + T cells, which facilitates the immune escape of tumor cells and promotes tumor growth[69] (Table 2).