Although the deletion of ch13q14 where human DLEU1 gene is localized in certain types of cancers supports the notion that DLEU1 is a tumor suppressor [1–4], the absence of DLEU1 gene in mouse ch13q14, together with the presence of at least several other tumor suppressor genes in this chromosomal locus, dampen the significance of loss of DLEU1 expression in tumorigenesis [23, 24]. This evidence concerns the gene DLEU1 and neoplasm.