EIF2AK2 and pulmonary venoocclusive disease: We previously demonstrated that the simultaneous administration of MMC and the PKR antagonist C16 (23), or the ISR inhibitor ISRIB (24, 25), prevents the development of PVOD phenotypes, such as pulmonary vascular remodeling and an elevation of the RV systolic pressure (RVSP) and an increase in the ratio of the RV weight to the left ventricle (LV) + septum (S) weight (RV/LV+S) (12).