Group

N

GSTM1

normal genotype

GSTM1

null genotype

GSTT1

normal genotype

GSTT1

null genotype

Smokers

100

99 (99%)

01 (1%)

94 (94%)

6 (6%)

Non smokers

100

86 (86%)

14 (14%)

72 (72%)

28 (28%)