Synonyms:BT, BTN, BTN1A1 Background:BTN1A1, also named as Butyrophilin subfamily 1 member A1, is a 526 amino acid protein, which contains 1 B30.2/SPRY domain and belongs to the immunoglobulin superfamily. BTN/MOG family. BTN1A1 localizes in the integral component of plasma membrane. BTN1A1 may function in the secretion of milk-fat droplets and may act as a specific membrane-associated receptor for the association of cytoplasmic droplets with the apical plasma membrane. BTN1A1 Inhibits the proliferation of CD4 and CD8 T-cells activated by anti-CD3 antibodies, T-cell metabolism and IL2 and IFNG secretion. The calculated molecular weight of BTN1A1 is a 59 kDa, but the modified BTN1A1 protein is about 65-75 kDa.