STAT3 and neoplasm: Jak2/STAT3 (Janus kinases 2/signal transducer and activator of transcription 3), MEK/ERK1/2 (mitogen-activated protein kinase/ extracellular signal-regulated kinase), p38 (mitogen-activated protein kinase p38) signaling pathways, and CXCR4 (C-X-C chemokine receptor type 4) axis are involved in promoting migration of MSCs toward tumor sites.47