From the paper ( https://www.sciencedirect.com/science/article/pii/S0149763421000804?via%3Dihub https://www.sciencedirect.com/science/article/pii/S014976342...

From the paper ( https://www.sciencedirect.com/science/article/pii/S0149763421000804?via%3Dihub https://www.sciencedirect.com/science/article/pii/S014976342... ) [we sought to integrate findings from a wide survey of the extant literature on s/g effects in human structural and functional brain imaging, using the search terms “sex” and “gender” in lieu of “sex difference” and “gender difference.” ] So they excluded studies that found differences.