Supporting the in vivo relevance of these in vitro data, immunohistochemical studies of tissue sections demonstrated strongly increased levels of pCADThr456 (Fig. 2g and Supplementary Fig. 4) and PDK1 (Supplementary Fig. 3b) in PDGFR-β+ pericytes within lungs of PAH patients as compared to controls (Fig. 2g, Supplementary Fig. 4 and Supplementary Fig. 3b depict sections from four lungs per group). Here, PDK1 is linked to pulmonary arterial hypertension.