Table 2.

Meta-analysis of the results

	OR (95% CI)	P Value	I 2 (%)	P Value
GSTT1
All	1.69 (1.33-2.16)	<0.0001	15	0.32
Type 1	1.71 (1.33-2.20)	<0.0001	35	0.20
GSTM1
All	1.59 (1.22-2.06)	0.0005	0	0.57
Type 1	1.51 (1.15-1.99)	0.003	0	0.71