Although cyclin-dependent kinase inhibitor 2A (CDKN2A) is frequently altered or deleted in a wide range of cancers and is known to be an important tumor suppressor gene, a study suggested that CDKN2A plays a key role in the formation and progression of larynx squamous cell carcinoma (Sasiadek et al., 2004). Here, CDKN2A is linked to in situ carcinoma.