Table 1. Cumulative population doublings of SIRT1, H363YSIRT1, Mock-transfected cells and untransfected cells.

Cells	Cumulative population doublings(PDs)	Number of test samples
untransfected cells	54–59	6
Mock vector	51–55	5
SIRT1	63–70	6
H363SIRT1	46–53	5