IL-12 was shown to drive intestinal pathology in early stages of colitis in mice lacking the nuclear factor kB (NF-kB) essential modulator (NEMO, also named IKKγ) specifically in intestinal epithelial cells (IECs), (NEMOIEC-KO), whereas IL-23 became important during later stages of the disease [233]. The gene discussed is IL23A; the disease is colitis.