A family of mammalian membrane glycoproteins characterized by extracellular IMMUNOGLOBULIN DOMAINS. Some members also have an intracellular B30.2-SPRY DOMAIN or SPRY DOMAIN. The butyrophilin protein (BTN) is expressed by MAMMARY GLAND EPITHELIUM during LACTATION; whereas other members are widely expressed in other tissues, including skeletal muscle, intestine, ERYTHROID CELLS (ERMAP protein); and nerve tissue (MYELIN-OLIGODENDROCYTE GLYCOPROTEIN).

Synonyms: 0, Butyrophilin, Butyrophilins