Similarly, the GSTM1-null genotype is linked to an elevated risk of POAG in smokers, according to a study by Stamenkovic et al., suggesting a possible gene-environment interaction [34] and a meta-analysis by Yu et al. demonstrated that combinations of GST polymorphisms are linked to an increased risk of glaucoma [35]. The gene discussed is GSTM1; the disease is open-angle glaucoma.