presume that the effect sizes associated with cGxE will be systematically larger. This is clearly a matter of some debate, as if certain types of cross-over interactions were prevalent, it would be possible. Nevertheless, the lessons we have learned from the history of gene finding underscore the need for researchers to be cognizant of the strong possibility that one is dealing with small effect sizes (or to provide strong justification for why larger effect sizes are expected), and to demonstrate that their samples are adequately powered.
