Fig. 4

Simulation results for pairwise variable importance measures. On the vertical axis, the proportion of simulation replications in which the true interaction between the two interacting SNPs is included in the top k SNP pairs according to the ranking by the variable importance measures is shown. On the horizontal axis, the number of k top SNP pairs considered is shown. If the importance measure included the true interaction in the top k SNP pairs, the interaction is detected. In (a) to (d), different simulation scenarios are shown. The parameters β _I and β _M correspond to the effects of the interacting SNPs and marginal-only SNPs, respectively. M A F _I and M A F _M are the minor allele frequencies of the corresponding SNPs. See Figures S25–S48 (Additional file 4) for results of all simulation scenarios for the single variable importance measures