Furthermore, among children without prenatal TSE, females with the GSTM1 null genotype had a significantly lower risk of developing childhood asthma compared with females with positive GSTM1 (9.4% versus 19.3%, P = 0.037, OR: 0.436, 95% CI: 0.197–0.966) (Table 3 and Figure 1). Here, GSTM1 is linked to asthma.