DNA/RNA extraction

Each patient and healthy control had 8–10 mL of blood drawn. First, blood samples were obtained from the cubital vein and then divided into two aliquots: one for the gene expression, for which TRIzol was used to preserve the blood samples [8], and the other aliquot was directly into an EDTA-containing tube for genotyping the selected SNPs. DNA/RNA extraction was then performed using a Norgen Biotek kit (Thorwold, ON, Canada) according to the manufacturer's guidelines. The quantity and quality of extracted DNA/RNA were investigated based on the ratio of optical density at the 260 and 280 nm wavelengths using (Qubit 4, Invitrogen, Waltham, MA, USA).