Table 3. Odds ratio analysis of combined GSTM1/GSTT1 phenotypes in patients and controls.

GSTM1/GSTT1 phenotypes	Patients (200) N (%)	Controls (182) N (%)	OR	95%CI	P
Non-null/Non-null	74 (37)	94 (51.7)	0.55	0.37-0.83	0.005
Non-null/Null	22 (11)	26 (14.3)	0.74	0.40-1.36	0.417
Null/Non-null	80 (40)	59 (32.4)	1.39	0.91-2.12	0.152
Null/Null	24 (12)	3 (1.6)	8.14	2.41-27.51	0.0001

N: Number of subjects; OR: odds ratio; 95%CI: 95% confidence interval; P: probability