ACTA1 and myocardial infarction: At least in mice with acute MI in vivo, both periostin and α-SMA were upregulated in cardiac fibroblasts by day 2 (Gil et al. 2022); in mice with cerebral infarction however, periostin levels were transiently suppressed in the ischemic region over 3 h post-insult (Shimamura et al. 2012).