- Impaired physiological responses to chronic hypoxia in mice partially deficient for hypoxia-inducible factor 1alpha. Yu, A.Y., Shimoda, L.A., Iyer, N.V., Huso, D.L., Sun, X., McWilliams, R., Beaty, T., Sham, J.S., Wiener, C.M., Sylvester, J.T., Semenza, G.L. J. Clin. Invest. (1999)