Yellow coat color mice in Cheryl Rosenfeld’s lab are not fortunate sons and daughters.Conventional knowledge says these mice will likely live fatter, more diseased lives than their black, brown and mottled (tiger-striped) siblings.

But recent data from her team at the University of Missouri calls into doubt influential studies on exposure to BPA and genistein, both estrogen-like chemicals known to influence obesity and disease in mice. Her research couldn’t replicate the results of previous studies by another research group.