Copyright information:Taken from "An application of conditional logistic regression and multifactor dimensionality reduction for detecting gene-gene Interactions on risk of myocardial infarction: The importance of model validation"BMC Bioinformatics 2004;5():49-49.Published online 30 Apr 2004PMCID:PMC419697.Copyright © 2004 Coffey et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. For each genotype combination, the number of cases is displayed in the left bar while the number of controls is displayed in the right-box. Darker shade indicates the high risk group. Note that the pattern of high and low risk for the polymorphism differs depending on the value of the polymorphism. This is evidence of epistasis or gene-gene interaction.