The first pieces of evidence that NF-kB can function as a tumor suppressor came from studies of chemically-induced skin cancer, in which inhibition of NF-kB via IĸB-SR expression in keratinocytes enhanced the multiplicity of squamous cell carcinomas in response to 7,12-Dimethylbenz(a)anthracene (DMBA). The gene discussed is NFKB1; the disease is skin neoplasm.