STAT3 and cancer: Others, including miR-940, miR-21-3p, miR-125b-5p, and miR-181d-5p, drive macrophages toward a tumor-supportive M2 phenotype by regulating the suppressor of cytokine signaling (SOCS)4/5/signal transducer and activator of transcription 3 (STAT3) pathways and enhancing cancer cell proliferation and migration.