Fig2A. Copyright: This image is from [doi:10.1002/dvdy.10441] Veltmaat JM; Van Veelen W; Thiery JP; Bellusci S, "Identification of the mammary line in mouse by Wnt10b expression." Dev Dyn 2004 Feb;229(2):349-56. Reprinted with permission of Wiley-Liss Inc. [PMID:14745960] .