miR-15b exerts its effects in these cancers through various mechanisms, such as the regulation of proliferation, apoptosis, epithelial–mesenchymal transition (EMT), and drug resistance, mediated by the NF-κB, STAT3, AKT/mTORC1, CDC42/PAK1, and β-catenin signalling pathways [174]. The gene discussed is STAT3; the disease is cancer.