- Spearow J, O Henley P, Doemeny P, Sera R, Leffler R, Sofos T, et al. Genetic variation in physiological sensitivity to estrogen in mice. APMIS. 2001;109:356-64 pubmed..These and other findings emphasize the need to identify and study genetic variation in sensitivity to estrogen in laboratory animal models used to assess the risk of xenobiotic estrogen exposure. ..