Table 1.

Synergistic indices of combination treatment with gefitinib and T0901317 after knockdown of LXRα or LXRβ expression. MGI, mean growth inhibition rate = growth rate of treated group/growth rate of untreated group. SI, synergistic index = expected growth inhibition rate/observed growth inhibition rate. An index of more than 1 indicates synergistic effect and < 1 indicates a less than additive effect

siRNA	Gefitinib		T0901317		Combination			SI
	MGI	P a	MGI	P a	Expectedb	Observedc	P a
NC	0.75	< 0.001	0.88	> 0.05	0.66	0.24	< 0.001	2.75
siLXRα	0.72	< 0.001	0.85	< 0.05	0.61	0.27	< 0.001	2.26
siLXRβ	0.83	< 0.05	0.83	< 0.05	0.69	0.65	< 0.001	1.06

^a P value (two‐sided) was calculated by one‐way ANOVA compared with no treatment.

^bExpected growth inhibition rate = MGI T0901317 × MGI gefitinib.

^cObserved growth inhibition rate = growth inhibition rate of combined treatment/growth rate of untreated group.