SOX9 and chronic kidney disease: In a next step, aortic mRNA expression profile of VSMC and bone-like marker genes revealed an up- and downregulation of Sox9/Runx2 (osteo-/chondrogenic marker genes) and Sm22-alpha (VSMC marker gene), respectively, in vehicle and TNAP inhibitor-treated CKD rats versus control rats, favoring a VSMC phenotypic switch into bone-like cells.