- FGF-23 transgenic mice demonstrate hypophosphatemic rickets with reduced expression of sodium phosphate cotransporter type IIa. Shimada, T., Urakawa, I., Yamazaki, Y., Hasegawa, H., Hino, R., Yoneya, T., Takeuchi, Y., Fujita, T., Fukumoto, S., Yamashita, T. Biochem. Biophys. Res. Commun. (2004)