HM1147 (clone TX69) is a monoclonal antibody against mouse CLM-5.This molecule, also known as MAIR-IV, LMIR4 or CD300ld1, is a member of the myeloid-associated immunoglobulin-like receptor family (MAIR, CD300). The CD300 family of receptors is an evolutionary conserved receptor family that belongs to the Ig superfamily and is expressed predominantly by the myeloid lineage. In mice, nine members have been reported with different nomenclature systems, such as myeloid-associated Ig-like receptor (MAIR), leukocyte mono-Ig-like receptor (LMIR), DC-derived Ig-like receptor (DIgR), and CMRF-35-like molecule (CLM). CD300 molecules act as either activating or inhibitory receptors through interactions with adaptor molecules, such as PAD12, DAP10, and FcRγ. CLM-5 is preferentially expressed on Gr-1+/Mac-1+ neutrophils in the peripheral blood, bone marrow, peritoneal cavity, and spleen. It is also found on Mac-1+/Gr-1+ macrophages and CD11c+ dendritic cells. Its expression is regulated by TLR ligands LPS and flagellin. In association with the immunoreceptor tyrosine based activating motif (ITAM)-bearing adaptor FcRγ, CLM-5 mediates activation signals for neutrophils thereby playing an important role for innate immunity such as the induction of proinflammatory cytokines TNF-a and IL-6.