A second common goal for studies of GxE interactions is the identification of novel factors that may contribute to the etiology of disease. This paper will focus on discovery of novel genetic loci, but it is important to consider that GxE can also be used to discover novel environmental factors. Genetic variation that impacts disease through interaction with environmental factors may not be readily detected in traditional GWAS analysis, particularly if marginal effects of the genetic factors are small [Gauderman, et al. 2013; Manolio, et al. 2009; Thomas 2010]. Therefore, there is growing motivation to use GEWIS, or other methods that incorporate environmental information, to identify novel risk loci. Notably, the focus is on discovery of new genetic loci that impact disease risk, more than on identifying novel GxE interactions per se. The expectation is that future studies will characterize any underlying GxE interaction.
