NFKB1 and cancer: Although tumor formation was also observed in IKK/NF-κB knockout (KO) mice to some degree, high incidence of colitis and spontaneous inflammation-associated tumor formation (colitis-associated cancer) was significantly enhanced in mice with constitutively active IKK/NF-κB in IECs (Shaked et al., 2012; Mikuda et al., 2020).