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). Here, WRN is linked to Werner syndrome.