TNFRSF1A and colitis: Moreover, mice deficient for TRAF2, the major TNFR1-Fn14 signaling connecting knot (Table 3), display severe colitis and increased apoptosis of IECs which both can be largely rescued by crossing with TNFR1-deficient mice (Piao et al., 2011; Piao J. H. et al., 2012).