Other hints that Mxd1 might suppress normal or neoplastic under different circumstances came from studies showing that its enforced expression repressed Myc+ Ras-mediated transformation of primary rat fibroblasts [178,179] and impaired the in vitro growth of established human cancers in a manner that is consistent with the model depicted in Figure 1 [181,182,183]. This evidence concerns the gene MXD1 and cancer.