Functions as an endocytic receptor on a small subset of myeloid cells specialized for the uptake and processing of material from dead cells. Recognizes filamentous form of actin in association with particular actin-binding domains of cytoskeletal proteins, including spectrin, exposed when cell membranes are damaged, and mediate the cross-presentation of dead-cell associated antigens in a Syk-dependent manner. Isoform 1: Monomer. Isoform 4: Homodimer. Isoform 4 expressed at high levels by CD8(+) dendritic cells (DCs), and at low levels by plasmacytoid DCs but not by other hematopoietic cells. Not glycosylated. N-glycosylated. Deficient mice shown no alteration of dendritic cell phenotype and numbers and the response of dendritic cells to innate stimuli is not altered. No alterations are found in leukocyte numbers or frequencies in spleen, lymph node or thymus, and mice appear normal and do not develop any obvious symptoms of autoimmune disease. mCLEC9