LILRA4, also known as ILT7 and CD85g, is a 499 amino acid (aa) type I transmembrane glycoprotein that contains four Ig-like domains in its extracellular region. LILRA4 is selectively expressed on plasmacytoid dendritic cells (pDC). It binds to BST2/CD317 on bone marrow stromal cells and associates with the gamma subunit of Fc epsilon RI. This receptor complex transmits signals that inhibit the TLR-induced production of type I interferon. The LILRA4-mediated interactions between pDC and tumor cells similarly inhibit the production of proinflammatory cytokines and contribute to reduced anti-tumor immune responses. Alternate splicing of human LILRA4 generates an isoform that lacks the N-terminal 43 aa of the extracellular domain.