Within the crosstalk between the muscle and the tumor microenvironment, decorin, which is secreted during exercise, has been shown to inhibit angiogenesis, carcinogenesis but also the TGFβ-induced fibrosis, through the interactions with different receptors, such as the epidermal growth factor receptor (EGFR) or insulin-like growth factor 1 receptor (IGF-1R), regulation of cell-cycle associated genes, but also miRNAs [312,313,314]. The gene discussed is EGFR; the disease is neoplasm.