It has been argued that p-CREB is important in the initiation of papilloma formation, while other transcription factors such as CCAAT/enhancer binding protein (C/EBP)–B [93,94] control later stages of tumour growth and Activator Protein 1 (AP1) [95,96,97] maintains tumour identity. The gene discussed is CREB1; the disease is papilloma.