However, upon exposure to hyperoxia (85% O2), PINK1 mRNA and protein levels were lower, while TOM20 protein content was noted to be higher in MSCs obtained from ELBW infants who died or developed moderate/severe BPD compared to MSCs from infants who survived with no/mild BPD (Fig. 4A,D). This evidence concerns the gene PINK1 and bronchopulmonary dysplasia.