Furthermore, Hanudel et al. have demonstrated that beta-thalassemia intermedia mice, which exhibit chronically high endogenous EPO levels, and wild-type mice with and without CKD, following a single intraperitoneal injection of exogenous EPO, display significant elevations in FGF23 mRNA levels in bone marrow and serum C-terminal FGF23 levels as opposed to serum intact FGF23 levels [191]. This evidence concerns the gene FGF23 and chronic kidney disease.