CDKN1A and myocardial infarction: Recent studies have reported that senescent biomarkers, including p16Ink4a and p21Cip1/Waf1, were increased in post-myocardial infarction mouse hearts, and costaining of α-SMA with p53 or p16 supports the possibility that senescent myofibroblast numbers are increased in infarct-border regions [186,187].