Required for normal bone mineralization. Interacts with FKBP11. Detected in embryonic bone (at protein level) (PubMed:18442316). Highly expressed in osteoblasts of adults and embryos. Expressed in primitive hemopoietic cells. In embryos at 16.5 dpf, detected in lumbar and thoracic vertebra, the basisphenoid bone, the mandible, the coronal suture between the frontal and parietal bones, the maxilla, the nasal bone and the palate, as well as in the bone collars of long bones and digital bones in hind limbs, and in the primary ossification center. By interferons. Palmitoylated. Embryonic lethality, leading to the birth of only 7% homozygous mutant pups, instead of the expected 25%. Only two out of eight pups were female. Crossing homozygous mice gave rise to about one sixth of the normal litter size, and many newborns died within 48 hours after birth. Homozygous newborns display no striking phenotype other than smaller bones and especially shorter long bones, and this phenotype persists into adulthood. The radius, ulna and tibia are frequently bent in newborns, but this is no longer the case in young adults. Membrane topology is controversial. The N-terminus is cytoplasmic and the C-terminus extracellular according to PubMed:24715519, while both the N-terminus and the C-terminus are extracellular according to PubMed:18442316. Belongs to the CD225/Dispanin family.