Number of times the considered polymorphisms appear in the ten top two- and three-way interactions when analyzing the different smoker groups.

Numbers in brackets are from the analysis of the two-way interactions. Numbers outside the brackets are from the analysis of the three-way interactions. The corresponding groupwise top ten two-way interactions are listed in Tables S12, S13, S14, S15 and S16, and the top ten three-way interactions are presented in Tables S17, S18, S19, S20 and S21.