CDKN2A and neoplasm: Finally, taking into consideration the role of ARF not only in the involution of HVS in the developing oculus (Thornton et al., 2005) but also in the involution of the mammary gland (Yi et al., 2004), it is plausible that ARF plays an even wider role than that of a tumor suppressor by acting as a potent “tissue remodeling factor” controlling transient histological structures.