After correction for sex and cardiovascular risk factors, the location of the PV was the highest predictive covariate for age at first stroke, with a hazard ratio (HR) for EGFr 1–6 PV versus EGFr 7–34 PV of 2.63 (95% confidence interval (CI) = 1.61–4.31, P < 0.001, Cox-regression analysis). The gene discussed is EGFR; the disease is stroke disorder.