Moreover, when colitis was spontaneously induced, the number of NK1.1+CD8+ T cells in the spleen and MLN from Yeti/CD1d KO mice with a prolapse were three- to four-fold higher compared to those from Yeti/CD1d KO mice without prolapse (Figure 3B), which strongly indicates that NK1.1+CD8+ T cells are pathogenic effector cells. The gene discussed is CD1D; the disease is colitis.