A set of differentially expressed RNAs relevant to PAH pathobiology were selected for validation of RNAseq quantification by real-time quantitative PCR, namely, NRG1, TRPC1, FBLN2, SESN1, SMAD5, and CCND3. SPAST was also selected for its stability across samples as a potential control gene (see Methods for details). The gene discussed is CCND3; the disease is pulmonary arterial hypertension.