LMNB1 and Hutchinson-Gilford progeria syndrome: Other characteristics of fibroblasts from individuals with HGPS result in an increase in the number of γ H2AX (phosphorylated histone H2AX, a marker of DNA double‐strand breaks) and loss of the heterochromatin marker tri‐methyl lysine 9 of core histone H3 (Tri‐Me‐K9) (Zhang et al, 2016) as well as a reduction in lamina‐associated polypeptide (LAP2α), lamin B1 or the heterochromatin adaptor between the nuclear lamina and chromatin (HP1α) (Scaffidi & Misteli, 2005).