TGFB1 and renal fibrosis: TGFβ1 can not only bind to the gene promoter by the Smad-dependent pathway to induce the transcription of fibrogenic molecules but also can cross talk with other signaling pathways through non-Smad-dependent pathways, including pp60c-src, epithelial growth factor receptor (EGFR), MAPK, p53, and PI3K/AKT [62] to form a signaling network and jointly enhance the expression of genes related to renal fibrosis [63].