IGF1 and skin cancer: Yu and collaborators tested a 20 m/min, 60 min/day and 5 days/week for 10 weeks protocol in mouse skin cancer model and found that exercised mice showed reduced IGF-1 bioavailability via IGFBP-3 augmented expression and IGF-1 downregulation via PTEN (a tumour suppressor gene) overexpression [158].