For example, MR was applied in a hypothesis-driven manner to assess the causality between selected biomarkers and stroke risk including C–C motif chemokine ligand 2(CCL2), Chitinase-3–like protein 1 (CHI3L1), C-reactive protein (CRP), cystatin C (CST3), apolipoprotein (a) (LPA), matrix metalloproteinase-12 (MMP12), and proprotein convertase subtilisin/Kexin type 9 (PCSK9) (Chong et al., 2019). The gene discussed is PCSK9; the disease is Stroke.