Many research are looking into the relationship between PAI-1 4G/5G polymorphisms and a variety of disorders, such as thrombosis (Zhang et al., 2020a), systemic lupus erythematosus (Anaya-Macias et al., 2020), thyroid eye disease (Katko et al., 2021), metabolic syndrome (Zhang et al., 2020b) and many more. This evidence concerns the gene SERPINE1 and metabolic syndrome.