There were no statistically significant interactions between the haplotype and smoking intensity or alcohol consumption (Table 3), or between the ASE-1 G-21A, RAI IVS1 A4364G and ERCC1 Asn118Asn polymorphisms, respectively, and smoking intensity or alcohol consumption (see Additional file 1), in relation to risk of colorectal cancer. Here, ERCC1 is linked to colorectal cancer.