GPX1 and ileocolitis: Ileocolitis in homozygous Gpx1/2‐double knockout mice (DKO; Gpx1−/−Gpx2−/−) occurs spontaneously on 3 backgrounds B6, 129/Sv, and B6.129 (Esworthy et al., 2011; Esworthy, Smith, & Chu, 2010; Lee et al., 2006).