NOS2 and kidney disorder: There was significant reduced plasma nitrate/nitrite level and serum NOS activity in TT genotype carriers compared with GG and GT genotypes, mentioning the Glu298Asp polymorphism as an important risk factor of DN to ESRD progression via NO levels reduction [294]. It has been suggested that the T allele and the TT genotype of eNOS 894G>T polymorphism, and the C allele and the CC genotype of − 786 T>C SNP, were significantly more prevalent among Egyptian diabetic patients suffering from nephropathy than those without nephropathy.