MCAM and cancer: To understand further the detailed knowledge of METCAM/MUC18-mediated suppression of the malignant propensity of ovarian carcinoma cells, perhaps some clues may be deduced from what we know from the METCAM/MCU18-mediated tumorigenesis of various tumor cell lines, such as cancers of breast and prostate, melanoma and nasopharyngeal carcinoma.