But in a recent larger case-control study in Tunisia that contained a total of 856 adult patients with T2D, Ezzidi et al. reported a significantly higher frequency of the 4G/4G genotype (OR 1.64, 95%CI 1.10 to 2.43), indicating 4G/4G in PAI-1 locus as a risk factor for DR [17]. The gene discussed is SERPINE1; the disease is type 2 diabetes mellitus.