CD56

CD56, also known as neural cell adhesion molecule, can regulate the immune activity of T cells and NK cells, and participate in synapse formation and neural development. CD56 can serve as a specific biomarker for NK/T cell lymphoma, but some research found the CD56 negative extranodal NK/T cell lymphoma, and patients have shorter survival time compared to being positive. Some scholars also pointed out that CD56 is expressed in some diffuse large B-cell lymphomas, which is related to high tumor burden. Moreover, CD56 is applied in the diagnosis of neuroendocrine neoplasm. For example, high expression of CD56 in small cell lung cancer suggests high invasiveness of the tumor. Meanwhile, CD56 is present in abnormal plasma cells, so it can assist in the diagnosis of multiple myeloma, and its expression deletion is a poor prognostic factor, speculated that down-regulation of CD56 will weaken cancer cell adhesion to promote tumor migration. In addition, decreased CD56 positivity rate is considered as one of the distinguishing features of papillary thyroid carcinoma from other thyroid lesions.