Similar to the iPSCs derived from the fibroblasts of HGPS and WS patients, HGPS- and WS-ESCs did not show any premature aging defects, indicating that pluripotent stem cells are able to conceal aging defects caused by LMNA mutation or WRN deficiency (Liu et al., 2012; Zhang et al., 2013). The gene discussed is WRN; the disease is Hutchinson-Gilford progeria syndrome.