Cardiac fibrosis is a key factor to affect the recovery of heart functions in patients with ischaemia heart diseases.22 As shown in Figure 2B,G, the infarction sizes in mice injected with adenovirus expressing Prrx2 shRNA were smaller than mice injected with adenovirus expressing negative control shRNA at the 30th day after MI surgery. The gene discussed is PRRX2; the disease is myocardial infarction.