Previously, we and others have found high levels of EMAP II at epithelial/mesenchymal cell interfaces of proliferating and differentiating cells in embryonic lungs [19], [20], [21], within dysplastic fibroproliferative regions of bronchopulmonary dysplasia (BPD) [22] and in emphysematous lungs [23], suggesting that EMAP II might regulate cell proliferation in organ development and disease. Here, AIMP1 is linked to bronchopulmonary dysplasia.