EGF serum concentrations in CTEPH patients (926.61 ± 576.61 pg/mL) were remarkably increased compared to controls (520.0 ± 464.2 pg/mL; p = 0.003) (Figure 3A), while EGF concentrations (766.0 ± 669.9 pg/mL) displayed no difference in the iPAH group compared to controls (511.9 ± 460.3 pg/mL; p = 0.311) (Figure 3B). This evidence concerns the gene EGF and chronic thromboembolic pulmonary hypertension.