AOM/DSS-treated wild-type mice receiving splenic IMCs from untreated CD2–Tff2 mice developed a lower number of tumours and a lower proportion of MDSC but a higher proportion of CD8+ cells in the colon compared with wild-type mice that received splenic IMC from Tff2-null mice (Fig. 3h–k). The gene discussed is CD2; the disease is infectious otitis media.