Estrogen influences class-switched memory B cell frequency only in humans with two X chromosomes. - Peckham H; Radziszewska A; Sikora J; de Gruijter NM; Restuadi R; Kartawinata M; Martin-Gutierrez L; Robinson GA; Deakin CT; Wedderburn LR; Jury EC; Butler G; et al. (The Journal of experimental medicine, 2025)