STRA6 and Anophthalmia: STRA6 not only is a vitamin A transporter but also is a cell-surface signaling receptor activated by the RBP–retinol complex [12].Mutations in STRA6 cause a broad spectrum of malformations including anophthalmia, congenital heart defects, diaphragmatic hernia, alveolar capillary dysplasia, lung hypoplasia, and mental retardation in human [13].