ILT6, also known as LILRA3, belongs to the ILT family. In humans, the ILT gene family includes up to 11 members. The extracellular portion of all members includes at least two and usually four immunoglobulin domains. ILT-2 through 5 are all inhibitory members having variable numbers of cytoplasmic ITIM domains. ILT6 lacks a transmembrane domain. The function of ILT6 is currently unknown. however it is highly homologous to other LILR genes, and can bind human leukocyte antigen (HLA) class I. Therefore, if secreted, the ILT6 might impair interactions of membrane-bound LILRs (such as LILRB1, an inhibitory receptor expressed on effector and memory CD8 T cells) with their HLA ligands, thus modulating immune reactions and influencing susceptibility to disease.