(111) found that irisin reversed the IL-6-induced epithelial-mesenchymal transition (EMT) in osteosarcoma cells by regulating the expression of E-cadherin, N-cadherin, vimentin, fibronectin, MMP-2, MMP-7 and MMP-9 through the signal transducers and activators of transcription 3 (STAT3)/Snail signaling pathway, implying that irisin may be a promising drug for OS treatment. Here, FNDC5 is linked to osteosarcoma.