DLL4 and idiopathic pulmonary arterial hypertension: Accordingly, in PAECs from IPAH patients (Figure 6C) and in BMPR2-silenced PAECs (Figure 6D), DLL4 not only induced PPARG transcription, but also increased mRNA expression of several PPARγ target genes (FABP4, CYP1A1, PGK1 and HK1).