P2RY4 and myocardial infarction: We observed an increase of T cell apoptosis in the basal PAT of P2Y4 KO mice compared to WT (31.3% ± 2.9% vs. 18.0% ± 2.4%, p = 0.0085) which was amplified in ischemic mice 7 days post-MI (61.0% ± 1.2% vs. 31.6% ± 2.9%, p < 0.0001) (Figures 3C,D).