STAT3 and neoplasm: Regarding miRNA, ovarian cancer-derived exosomes deliver miRNAs (miR-21-3p, miR-125b-5p, miR-181d-5p and miR940) to macrophages and elicit the polarization of tumor-associated macrophages (TAMs) by regulating the suppressor of cytokine signaling (SOCS)4/5/signal transducer and activator of transcription 3 (STAT3) pathways [44,45].