EIF2AK4 and pulmonary venoocclusive disease: Loss of Gcn2 function leads to pulmonary disorders (18, 19, 20, 21), and we showed that low concentrations of Gcn2iB can activate Gcn2 R585Q mutant derived from a PVOD patient (Fig. 8, C and D), which offers new therapeutic strategies for treatment of those expressing missense or truncated Gcn2 mutant proteins that retain an intact protein kinase domain.