Although cells from HGPS patients show a decrease of heterochromatin but are devoid of SAHFs (Scaffidi and Misteli, 2006; Shumaker et al., 2006), recent findings uncovered similarities between SAHF- and progerin-induced senescence with the loss of contacts of GC-poor LADs prior to SAHF formation suggesting a two-step mechanism for SAHF formation involving also disruption of the NL (Chandra et al., 2015). This evidence concerns the gene LMNA and Hutchinson-Gilford progeria syndrome.