STAT3 and neoplasm: Furthermore, hypoxia induces the enrichment of released exosomes with various miRNAs from ovarian cancer, including miR-940 (Chen et al., 2017), miR-21-3p, miR-125b-5p, and miR-181d-5p (Chen et al., 2018), miR-222-3p (Ying et al., 2016), which can be transmitted to macrophages via exosomes and stimulate the M2 phenotype polarization, leading to the (SOCS)2/4/5/STAT3 cytokine signaling pathway suppression and tumor progression.