TTN and diabetic kidney disease: On the other hand, some of the polymorphisms in genes coding for TPO, titin (TTN), Shugoshin 2 (SGO2); NOS3; PDZ and LIM domain 1 (PDLIM1), CLU, glutathione peroxidase 4 (GPX4), thioredoxin reductase 2 (TXNRD2), epoxide hydroxylase 2 (EPHX2), metallothionein-like protein 5 (MTL5), eosinophil peroxidase (EPX), glutathione peroxidase 3 (GPX3), soluble glutathione serine transferase alpha 7Ρ (GSTA7P), glutathione peroxidase 6 (GPX6), OXR1; and glutathione S-transferase A4 (GSTA4) conferred increased risk for DKD [47].