Irisin stimulates cell proliferation by targeting the PI3K/AKT pathway in human hepatocellular carcinoma (Shi et al., 2017), while it suppresses cell proliferation of MCF-7 and MDA-MB-231 breast cancer malignant cell lines (Gannon et al., 2015) and pancreatic cancer cells (Liu et al., 2018). This evidence concerns the gene AKT1 and breast cancer.