CRIPTO and cancer: In this study, we have analyzed for the first time how Cripto haploinsufficiency may affect in vivo cancer development by treating Cripto heterozygous mice (14,36) with the mutagenic agent azoxymethane (AOM) that exerts colonotropic carcinogenicity (37,38) and has been widely used to investigate the pathology and genetics of colorectal cancer in rodents (37,39).