In contrast, under hyperoxic conditions, the expression of the 6 retinoid receptors were significantly reduced at P4 (RARγ, RXRα), P9 (RARα, RARβ, RXRγ), and P15 (RARβ, RARγ, RXRα, RXRβ, RXRγ), which could interfere with alveologenesis and contribute to BPD development. This evidence concerns the gene RXRG and bronchopulmonary dysplasia.