CD63 is widely expressed in hematopoietic and non-hematopoietic cells, such as sweat glands, langerharv's islands, pituitary, pancreas, peribronchial glands, pandi cells and prostate cells. Monocytes, macrophages, activated platelets, etc. CD63 is mainly used in the judging of malignant melanoma. As a tumor suppressor gene, CD63 can inhibit the spread and metastasis of malignant melanoma.