HTRA1 and stroke disorder: The median of relative expression levels of HTRA1 in the leukocytes of stroke cases was 1.68-fold lower than in the controls (HTRA1 relative expression, median and IQR of cases: 0.56 (0.25–1.42), median and IQR of controls: 0.94 (0.36–2.52), P = 0.023, Fig. 2A).