FNDC5 and neoplasm: The search terms included ‘irisin’ or ‘Fndc5’ with ‘cancer’, ‘tumour’, ‘neoplasia’, ‘oncogenesis’, ‘cell proliferation’, ‘apoptosis’, ‘metastasis’, ‘epithelial-mesenchymal transition (EMT)’, ‘IGF-1’, and ‘PI3K/Akt/mTOR pathway’.