Table 4.

Variant allele frequencies in NCF and CF.

Polymorphisms	Variant allele	NCF	CF	p-value
NQO1	Ta	0.32	0.18	0.233
CYP2E1 1053C > T	Ca	0.21	0.14	0.394
CYP2E17632T > A	Aa	0.06	0.11	0.284
GSTM1	nulla	0.26	0.34	0.452
GSTT1	nulla	0.20	0.26	0.539
MPO	Ab	0.30	0.31	0.639

^a alleles related to risk; ^b alleles related to protection.