According to the subgroup analyses stratified according to age, sex, hypertension, AF, admission NIHSS score, smoking, alcohol consumption, stroke etiology, and acute reperfusion treatment (with or without IVT and/or EVT), higher serum HO‐1 levels were significantly associated with decreased risk of poor functional outcome in most subgroups (Figure S3). This evidence concerns the gene HMOX1 and hypertensive disorder.