CHUK and papilloma: These Ikkα+/− SCCs lost the WT Ikkα allele, and IKK kinase activity is increased compared to Ikkα+/+ carcinomas, which is correlated with increased ERK activity, poorly differentiated cell features, and WT Ikkα allele loss [19], indicating that IKKα loss promotes the malignant conversion from papillomas to carcinomas.