HOXA9 and neuroblastoma: Notably, the four human HOXD proteins (HOXD8, HOXD9, HOXD10, HOXD12) with both anti-growth and differentiation-inducing activities in neuroblastoma cells correspond to the Drosophila Hox proteins abd-A (HOXD8) and Abd-B (HOXD9, HOXD10, HOX12) that are responsible for specifying the abdomen [43].