Figure 4. Effects of hTERT and its mutants on epigenetic ageing of human primary neonatal fibroblasts. Ages of primary human neonatal fibroblasts bearing empty vector (blue dots), wildtype hTERT (A), IA mutant (B), N-DAT116 mutant (C) or N-DAT92 mutant (D) were determined using the pan-tissue clock (left panel) and the skin & blood clock (right panel). (E) Composite plot of all the hTERT mutants. The ages of cells from a selection of passages are plotted against cumulative population doubling (CPD) that corresponded to the passages of cells that were analysed.