**Human ERα and ERβ Splice Variants: Understanding Their Domain Structure in Relation to Their Biological Roles in Breast Cancer Cell Proliferation**

Ana M. Sotoca1,2, Jacques Vervoort2,

Ivonne M.C.M. Rietjens1 and Jan-Åke Gustafsson3,4 *1Toxicology section, Wageningen University, Wageningen 2Laboratory of Biochemistry, Wageningen University, Wageningen 3Department of Biology and Biochemistry, Center for Nuclear Receptors and Cell Signaling, University of Houston, Science & Engineering Research Center, Houston 4Department of Biosciences and Nutrition, Karolinska Institutet, Novum, Huddinge 1,2The Netherlands 3USA* 

*4Sweden* 
