We were also interested in whether Lgr5 contributes to tumorigenesis, as it has been suggested to be a potential therapeutic target for various tumor types and may have implications for treating basal-like breast cancers.22–24 We therefore ablated Lgr5 function in a mouse model of human basal-like breast cancer using the Lgr5KI strategy described above.25, 26 EpCAMHIGH; CD49fHIGH; GFPPOS cells were isolated from E18 Lgr5KIHET and Lgr5KIHOM embryos carrying the C3(1)TAg allele and injected into cleared fat pads of six recipient mice. Here, LGR5 is linked to breast carcinoma.