KL and chronic kidney disease: As DMP1, a key regulator of FGF23 [13], [14], is also expressed in blood vessels and kidney tissues [26], [27], we explored the potential (beneficial or harmful) role of DMP1 in soft tissue calcification within Dmp1−/−kl/kl compound mice lacking both Klotho and Dmp1. This model displayed high phosphate retention and increased FGF23 levels which resemble chronic kidney disease (CKD).