Further, the largest subclass of human ZF proteins additionally contain Krüppel-associated box (KRAB) domains, and most of these proteins are thought to mediate transcriptional repression via interactions with chromatin-remodeling factors [13, 14] and many of them have been found to bind and repress retroelements [15–18]; these ZFs may be of particular interest as changes in chromatin and altered expression of transposable elements are both observed in cancers [19, 20]. This evidence concerns the gene CREBZF and cancer.