HOXD13 and neoplasm: Having determined that the differential growth advantage of EWS-FLI1+ stylopod cells after 12 days in culture was neither dependent on Hoxd13, nor associated with enhanced expression of other posterior HoxD genes, we next evaluated expression of Dkk2, Prkcb, and Gli1, given that early changes in expression of these tumor-promoting genes had been apparent after two days (see Figure 3 above).