Indeed, the present understanding of KLF5 and glycolysis via related TGF-β and HIF-1α in fibrosis is only the expected hypothesis for investigating cardiac fibrosis in the future; we point out that the function of KLF5 and related factors in cancer may aid and guide the possible ways to study and provide more understanding of fibrosis in the heart. This evidence concerns the gene KLF5 and fibrosis.