Fc Receptor-Like Protein 4 (FCRL4) Antibody

Background

Fc Receptor Like 4 (FCRL4) is a transmembrane protein expressed on a subset of memory B cells, predominantly in mucosal and inflamed tissues. Unlike other Fc receptor-like proteins, FCRL4 has a distinct role in dampening B cell receptor (BCR) signaling. It contains immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in its cytoplasmic tail, allowing it to inhibit activation signals and antibody production. FCRL4 expression is often upregulated in chronic infections and autoimmune diseases, where it is associated with an exhausted B cell phenotype, potentially contributing to immune dysregulation and impaired humoral responses.