Shown are fibroblasts from a Hutchinson-Gilford Progeria syndrome patient which carries a mutation in the gene for lamin A (red), a major component of the nuclear lamina. The morphology of the envelope shows progressive abnormalities that increase with the number of passages. The passage 6 cell (left) appears much like the wildtype while passage 13 (center) and 26 (right) show nuclear envelope abnormalities. See Fig 1 in R.G. Goldman et al. 2004 Proc Natl Acad Sci 101:8963-8968.