When VSMCs are exposed to elevated phosphate concentrations in the extracellular environment, as is the case in CKD patients, osteo/chondrogenic differentiation (as evidenced by increased Runx2, β-catenin, osteocalcin, osteopontin and ALP expression) is initiated via increased BMP-2-SMAD signalling. Here, RUNX2 is linked to chronic kidney disease.