BAFF also known as TALL-1, TNFSF13B is a cytokine that belongs to the tumor necrosis factor (TNF) ligand family and plays a pivotal role in immune regulation. BAFF is predominantly expressed in peripheral blood leukocytes, monocytes, and macrophages, where BAFF is essential for modulating infections, inflammation, autoimmune diseases, and tissue homeostasis. BAFF functions as a potent B cell stimulatory factor, significantly influencing B cell proliferation and serving as a key mediator in B cell-associated autoimmune disorders. BAFF′s structure features a C-terminal extracellular domain with a jelly roll topography, which is crucial for ligand trimerization. The interaction between BAFF and its receptor triggers oligomerization, leading to the initiation of downstream signaling pathways.