CCN2 and renal fibrosis: Moreover, studies on both human tubular epithelial HK-2 cells and mouse tubular epithelial MCT cells revealed that this modification of PTEN can be induced by factors linked to renal fibrosis, such as transforming growth factor beta (TGF-β), connective tissue growth factor (CTGF), sonic hedgehog (SHH), interleukin (IL)-6, and hyperglycemia [24].