GSTM1 and colitis: Anti-IL-7Rα-treated Hb-infected mice were normal with well-formed fecal pellets in the distal colon and normal diameter of the proximal colon and were generally considered normal histologically (Figure 1B, anti-IL-7R M595/500 Hb) or had some mild focal colitis (anti-IL-7R M595/50 Hb).