Similar to their effect on renal fibrosis, irbesartan, but not losartan, treatment significantly reduced fibrosis in the heart (Figure 6), whereas the reduction of fibrosis in the heart by irbesartan was also attenuated by treatment with GW9662, a PPARγ antagonist, or anti‐HGF neutralizing antibody. The gene discussed is PPARG; the disease is renal fibrosis.