CHUK and benign neoplasm: Although the chemical carcinogen stimulates IKKα expression in the normal skin and early benign tumors [19,42], the heterozygous Ikkα gene (Ikkα+/−) expresses a half dose of induced IKKα in response to stimuli compared to WT (Ikkα+/+), which attenuates IKKα anti-tumor activity.