Table 2.

IDO1 activity in human cancer cells

Sample	HPLC-DAD	LC-MS/MS	p-Value
	IDO1 activity ± SD (nmol/mg per min)
MDA-MB-231
#1	0.0090 ± 0.0016	0.0095 ± 0.0002	0.3160
#2	0.0120 ± 0.0031	0.0146 ± 0.0038	0.2800
#3	0.0080 ± 0.0011	0.0075 ± 0.0003	0.7296
#4	0.0060 ± 0.0002	0.0051 ± 0.0004	0.9680
#5	0.0116 ± 0.0028	0.0135 ± 0.0010	0.2010
#6	0.0114 ± 0.0026	0.0124 ± 0.0003	0.3014
SK-OV-3
#7	4.4199 ± 0.3793	3.7689 ± 0.0911	0.9488
#8	3.5507 ± 0.3180	3.4921 ± 0.1692	0.5909
#9	5.0456 ± 0.2751	4.3200 ± 0.1314	0.9704
#10	5.1489 ± 0.4440	4.3085 ± 0.0899	0.9237
#11	4.1634 ± 0.7006	3.9443 ± 0.3253	0.6577
#12	4.3314 ± 1.4730	3.9034 ± 0.3076	0.6642

SD: standard deviation from 3 measurements.