STAT3 and renal fibrosis: Several reviews summarized the response to leptin, IL-6, or high glucose, the signal transducer and activator of transcription (STAT)3 can be activated by tyrosine phosphorylation at tyrosine residues via Janus tyrosine kinases in renal cells, which might contribute to glomerulosclerosis and renal fibrosis [18,24,27].