A systematic review exploring the prognostic value of CD-63 in different tumours was published in 2018, by Koh et al,127 which reported an inverse relationship of CD-63 expression with cancers of the ovaries, breasts, colon and lungs.123,128, , –131 However it was found that CD-63 although not overly expressed in the tumor cells helped in the increased production of proteins which promote metastasis and invasion, thus showing higher levels in the plasma as compared to the tumor tissue itself.132,133. This evidence concerns the gene CD63 and cancer.