Although a small case-control study consisting of 36 leiomyoma cases and 29 controls, Huang et al. found that urinary ∑DEHP is associated with an increased risk of leiomyoma after adjusting for the GSTM1 genotype, which is the first study to explore the gene-environmental interaction of phthalate exposure and GSTM1 polymorphisms [24]. Here, GSTM1 is linked to leiomyoma.