Examples of other hypermethylated genes used to predict poor clinical prognosis include CDKN2A in colorectal cancer [81], RASSF1A and APC in breast cancer [82], the apoptosis-associated gene DAPK1 in lung and head and neck cancers [83,84], and CDKN2A, RASSF1A, cadherin 13 (CDH13) and APC in stage I NSCLC [85]. Here, CDKN2A is linked to head and neck cancer.