However, these data were from mouse models only; it is conceivable that murine Ldb1 has different effects and targets than human LDB1. Another explanation of the contradictory results of many studies on Ldb1 may be organspecific effects of Ldb1: While inactivation of Ldb1 led to an increase in tumor growth in murine hepatocellular carcinoma [15], its overexpression in mammary glands promoted breast tumorigenesis [36, 37]. This evidence concerns the gene LDB1 and neoplasm.