Sialomucin that may play a key role in hematopoiesis by facilitating the adhesion of CD34(+) cells to the stroma and by negatively regulating CD34(+)CD38(lo/-) cell proliferation. Modulates the migration of umbilical cord blood CD133+ cells and this is mediated through the CXCL12/CXCR4 axis. May play an important role in prostate cancer metastasis and the infiltration of bone marrow by cancer cells. Promotes myogenesis by enhancing CXCR4-dependent cell motility. Positively regulates myoblast migration and promotes myoblast fusion into myotubes (By similarity). {ECO:0000250|UniProtKB:Q9R0L9, ECO:0000269|PubMed:16859559, ECO:0000269|PubMed:17077324, ECO:0000269|PubMed:9763543}. This is the function of Ensembl gene identifier ENSG00000135535 (CD164, CD164 molecule).