TET1 and pulmonary arterial hypertension: Furthermore, the restoration of SIN3a had a broader impact on gene expression, resulting in the upregulation of TET1, ELP3, and MBD4 and the downregulation of DNMT1, EZH2, SUZ12, and CTCF, which led to a reduction in the methylation level of the BMPR2 promoter region and the re-establishment of BMPR2 expression in the animal models of PAH [20].