CD307c is a type I transmembrane glycoprotein of the Fc receptor family. It contains both ITAM and ITIM motifs in its cytoplasmic domain. CD307c is expressed on the surface of NK cells, and T, Treg, B and plasma cell subsets. It seems to play a role in the regulation of immune response. Defects in CD307c function can result in autoimmune diseases, e.g. rheumatoid arthritis or systemic lupus erythematosus.