A key role of HOX genes in cancer thus seems to be the repression of Fos, DUSP1, and ATF3 expression, which in turn inhibits apoptosis, and correspondingly DUSP1 [14] and ATF3 [15] have both previously been identified as potential tumour suppressor genes in prostate cancer, although the role of Fos in this context is less clear. This evidence concerns the gene FOS and neoplasm.