CCN2 and pulmonary arterial hypertension: On other hand, plasma connective tissue growth factor (CTGF) levels are higher in PAH associated with congenital heart disease (CHD) and in PAH patients [72], and it has been demonstrated that this growth factor is up-regulated in senescent cells and contributes, similar to TGF-β, to the induction of paracrine senescence [73,74].