The present invention relates to a method for determining variable response to statin therapy in patients afflicted with or susceptible to develop cardiovascular diseases, hypercholesterolemia, Diabetes and metabolic disorders involving high baseline plasma lipid level such as high LDL-C level, comprising detecting the presence or absence of the Pro 155T hr (C463A) variant in the Organic Anion Transporting Polypeptide-C(OATP-C) gene, wherein the presence of said variant is indicative of superior response to statin therapy. It also concerns tailored treatment of different populations of patients according to the Pro155Thr (C463A) variant genotype.