Table 4. Relative gene expression levels (RT qPCR data) of purine/thiopurine related genes vs. metabolite profiles.^a .

	All (n = 54)		R20 (n = 19)		Median (n = 17)		R4 (n = 18)		R20 vs. Median	R20 vs. R4	R4 vs. Median
Gene	Median	Range	Median	Range	Median	Range	Median	Range	P	P	P
ENTPD1	1.70	1.00–4.85	1.61	1.00–4.85	1.83	1.15–3.61	1.77	1.18–4.25	0.57	0.26	0.52
HPRT1	1.42	1.00–1.97	1.46	1.00–1.93	1.36	1.09–1.97	1.42	1.25–1.64	0.15	0.31	0.59
IMPDH2	1.86	1.00–2.95	1.92	1.47–2.95	1.89	1.12–2.25	1.75	1.00–2.19	0.57	0.05	0.22
MGST2	1.86	1.00–4.90	1.66	1.06–4.08	2.11	1.00–3.06	2.17	1.59–4.90	0.04	0.01	0.46
NME6	1.58	1.00–2.35	1.38	1. 5–2.05	1.71	1.00–2.35	1.62	1.19–2.19	0.06	0.03	0.73
NT5E	9.25	1.00–32.14	11.28	2.12–32.14	8.88	2.30–18.74	6.93	1.00–26.94	0.17	0.05	0.24
RAC1	1.80	1.00–2.66	1.60	1.01–2.44	1.85	1.00–2.54	1.97	1.28–2.66	0.26	0.05	0.42
SLC29A2	2.22	1.00–3.68	2.37	1.42–3.39	2.16	1.14–3.68	1.97	1.00–3.43	0.29	0.10	0.55
TPMT	1.53	1.00–2.72	1.41	1.00–2.49	1.52	1.10–2.64	1.78	1.30–2.72	0.53	0.02	0.23

^aReverse transcription qPCR data, in the expanded patient cohort (n = 54), of genes showing significant results either in a Spearman rank order correlation analysis or in a Mann-Whitney U-test. Significant group differences are indicated in bold. Abbreviations: R20; meTIMP/6-TGN concentration ratio >20, Median; median metabolizer, R4; meTIMP/6-TGN concentration ratio ≤5.7.