Technical Articles

This article focuses on the molecular characteristics and biological functions of the FMC63 single-chain variable fragment, systematically elaborating on its structural basis as constructed from the heavy chain variable region and light chain variable region of a murine anti-human CD19 IgG2a monoclonal antibody linked by a flexible peptide linker, analyzing its high-specificity binding properties with human CD19 widely expressed on the surface of normal B cells and B-cell malignancies, and discussing its central position as the classic extracellular antigen-recognition domain targeting CD19 in CAR-T cells within approved CAR-T therapies.