The CHANCE-2 randomized trial addressed a clinically important example of pharmacogenetics in stroke prevention. More than 6,000 Chinese patients with minor ischemic stroke or high-risk TIA who carried CYP2C19 loss-of-function alleles were assigned to ticagrelor or clopidogrel, both combined with aspirin for the short initial treatment period. Stroke occurred less often during 90-day follow-up with ticagrelor than with clopidogrel, while severe or moderate bleeding was similar between groups; overall bleeding was more frequent with ticagrelor. The study shows how genotype can influence the effectiveness of a commonly used secondary-prevention strategy. The population was almost entirely Han Chinese, so the magnitude of benefit may not transfer directly to every population. Nevertheless, the trial supports the broader principle of precision stroke medicine: when clopidogrel activation is impaired by genotype, an alternative P2Y12 strategy may reduce early recurrent stroke. For HCPs, pharmacogenetic testing is most useful when interpreted within local guidelines, patient bleeding risk and available testing pathways. The study directly complements IANCON's focus on stroke recurrence and newer approaches to secondary prevention.