Both clinical and preclinical researchers are routinely required to consider sex differences, but human genetic studies have largely considered sex only by regressing it out of statistical models. Most studies that assess sex in any way just include it as a covariate in their analyses, along with other relevant confounding variables (e.g., age). However, this approach does not directly assess whether genetic effects are dependent on sex, but instead provides a loose estimate of sex effects that may or may not be examined more closely. In other words, sex is often included as a control variable, and the variance attributable to sex is not closely examined; it is essentially parceled out and discarded.
