Table 1. Doubling time of the cells.

Cells (HPV+)	DT ± SEM	Cells (HPV−)	DT ± SEM	Primary cells	DT ± SEM
SiHa	21.98 ± 1.08	C33A	27.69 ± 4.32	PHK	60.52 ± 5.34
Caski	24.92 ± 1.26	HaCaT	24.54 ± 2.65	HEL	52.04 ± 6.73
HeLa	24.06 ± 1.02	SCC-120	27.76 ± 2.15	PET	110.47 ± 11.21
CK1	25.79 ± 1.10	SCC-4	40.71 ± 2.11
SCC-147	43.42 ± 6.12	SCC-9	33.89 ± 2.08
UM-SCC-47	37.63 ± 1.47	UM-SCC-38	35.54 ± 3.11
UM-SCC-104	62.07 ± 5.43
UT-SCC-45	38.52 ± 3.95
UD-SCC-2	43.31 ± 5.55

Mean doubling time (DT), in hours, and SEM of the cell lines. At least 3 experiments were performed per cell line. Untreated cells were seeded in 96 well plates and counted at the same time points as for the antiproliferative experiments. DT was calculated with the formula: DT = (t₂–t₁)/(log₂N₂−log₂N₁), where t₁ and t₂ are the times (hours) at which the cells were counted, and N₁ and N₂ are the cell numbers at times t₁ and t₂.