It has been confirmed that CD166 is abnormally expressed in a variety of tumor cells and plays an important role in tumor invasion and metastasis, such as breast cancer [18], liver cancer [19], stomach cancer [20], colon cancer [21], malignant melanoma [22], salivary gland tumor [23], prostate cancer [24], and so forth. The gene discussed is ALCAM; the disease is prostate carcinoma.