ITSN2 and Hutchinson-Gilford progeria syndrome: Increased expression of ING1a and ITSN2 during replicative senescence, in a premature cell aging model (HGPS), and in response to other forms of stress suggests that premature aging syndromes such as HGPS, SIPS, and replicative senescence may have many components in common, despite being initiated by different agents.