Recently, in the EHitsn-KOITSN+/− PAH mouse model for plexiform arteriopathy, Xist expression levels were increased in female PAH mice compared to the male mice or female WT mice.200 Noteworthy, female EHitsn-KOITSN+/− mice showed worsened vascular remodelling compared to their male equals. Here, XIST is linked to pulmonary arterial hypertension.