CD45/LCA

CD45, also known as leukocyte common antigen (LCA), is a transmembrane glycoprotein that widely exists in all immune and hematopoietic cells except mature red blood cells. It can affect the signal transduction of T cell receptors and B cell receptors by regulating the phosphorylation status of Src family kinases, thereby determining the strength and specificity of immune response. CD45 is expressed in almost all lymphomas, and it can also be expressed in various hematopoietic system diseases such as acute myeloid leukemia, acute lymphocytic leukemia, and chronic lymphocytic leukemia. Therefore, CD45 has become an important differential biomarker for lymphoid and hematopoietic system tumors. Among them, there is CD45 expression deletion in some large B cell lymphoma and follicular lymphoma, speculated that it is caused by down-regulation of gene expression. In addition, the low expression of CD45 is considered to be associated with the malignant development of head and neck squamous cell carcinoma and colorectal cancer. But some scholars pointed out that its high expression may induce poor prognosis in multiple myeloma patients by participating in tumor immune escape.