Moreover, HGPS patient fibroblasts and Zmpste24-deficient MEFs are more sensitive to DNA-damaging agents and are retarded in the recruitment of DNA damage response proteins like p53 binding protein 1 (53BP1), indicating the existence of defective DNA repair machinery, such as homologous recombination DNA repair, within these cells [7]. Here, TP53BP1 is linked to Hutchinson-Gilford progeria syndrome.