CYP2C19 and Stroke: The current Ticagrelor or Clopidogrel with Aspirin in High-risk patients with Acute Non-disabling Cerebrovascular Events II (CHANCE-2) trial verified the hypothesis that DAPT including aspirin and ticagrelor would be superior to aspirin and clopidogrel in reducing the risk of subsequent strokes among Chinese patients with minor stroke or high-risk TIA carrying the CYP2C19 loss-of-function alleles (Wang et al., 2021).