BTN2A1

Duplication events have led to three paralogues of BTN2A in primates: BTN2A1, BTN2A2, and BTN2A3. In humans, only BTN2A1 has been functionally characterised; it has been detected on epithelial cells and leukocytes, and identified as a novel ligand of dendritic cell-specific ICAM-3 grabbing nonintegrin (DCSIGN), a C-type lectin receptor that acts as an internalization receptor for HIV-1, HCV, and other pathogens. BTN2A2 mRNA has been shown to be expressed in circulating human immune cells.