TCF7L2 and idiopathic pulmonary arterial hypertension: Similarly, the target genes driving the classification in an independent RNAseq dataset, TCF7L2, which ranked highest in importance has previously been seen to be differentially expressed in the lung tissue of IPAH patients [49] as well as in the cardiac muscle tissue in a rat model [50] Some of these target genes also showed weak to moderate correlation with available clinical features, such as lung function forced vital capacity (Supplementary Table 10).