Ras association domain family 4 (RASSF4) is a tumor suppressor protein that is widely expressed in normal tissues; however, loss of expression due to DNA hypermethylation is related to nasopharyngeal carcinoma [285], non-small cell lung cancer [286], colorectal cancer [287], and head and neck cancers [288]. The gene discussed is RASSF4; the disease is head and neck cancer.