MX1 and chronic kidney disease: In this study, we investigated the effects of TGF-β receptor I (TβRI) overexpression on bone remodeling during CKD; we generated CKD by a 5/6 nephrectomy with angiotensin II in transgenic mice expressing constitutively active TβRI under the control of Mx1-Cre (Mx1;TβRICA mice).