For example, CAD expression is associated with poorer prognosis in patients with oral squamous cell carcinoma [11] and colorectal cancer [12], whereas other studies with human colon [13] and breast cancer cell lines [13, 14], and gastric cancer [15] show the function of CAD as a repressor of cancer cell migration or invasion. The gene discussed is CAD; the disease is oral cavity squamous cell carcinoma.