Table 1. Growth inhibition of HT29 or HCT116 cell lines exposed to XR5944, 5-FU, or SN38.

	Cell line (IC50, nM)
	HT29	HCT116
XR5944	0.6±0.2	1.0±0.4
5-FU	1616±1100	5635±930
SN38	4.2±0.7	8.4±3.3

5-FU=5-fluorouracil.

Cells were exposed for 5 days and the concentration that inhibits 50% of growth compared to controls was determined. Values are the mean of at least three independent experiments±s.d.