PRDM9 and diabetic kidney disease: Recent studies have demonstrated that abnormal expression or activity of histones methyltransferases are associated with development and prognostic state of various kidney diseases in human and animal models such as acute kidney injury (AKI), chronic kidney disease (CKD), diabetic nephropathy (DN), polycystic kidney disease, and renal cell carcinoma (Portela and Esteller, 2010; Takawa et al., 2011; Dressler and Patel, 2015; McGrath and Trojer, 2015; Cai et al., 2016; Siddiqi et al., 2016).