Cluster of differentiation 19 (CD19) is a glycoprotein found on the surface of B cells, pivotal in their development, activation, and differentiation processes. Serving as a co-receptor alongside the B cell receptor (BCR), CD19 aids in regulating B cell signaling and antigen recognition. It is widely employed as a biomarker for B cell malignancies like B cell lymphomas and leukemias. Therapeutically, CD19-targeted treatments, such as monoclonal antibodies and chimeric antigen receptor (CAR) T cell therapies, have transformed the management of these cancers by specifically targeting CD19-expressing cells while sparing healthy ones. Consequently, CD19 remains a crucial focus in both research and clinical practices related to B cell disorders.
