AKT1 and pulmonary arterial hypertension: This hypothesis is supported by three findings (Supplementary Fig. 8): (i) PDK1 mRNA expression was upregulated by PDGF-BB in both control and PAH pericytes and this was prevented by CNP (Supplementary Fig. 8a); (ii) specific inhibitors of AKT and mTORC prevented the stimulatory effect of PDGF-BB on PDK1 protein expression (Supplementary Fig. 8b); and (iii) inhibition of cGKI (10 μM Rp-8-Br-PET-cGMPs, 20 min pretreatment), abolished the inhibitory CNP effect on PDGF-BB induced PDK1 expression (Supplementary Fig. 8c).