SDC2, compositions that comprise SDC2, vectors encoding SDC2 and compounds that modulate expression of SDC2 by cells are used for treatment of mammalian, e.g. human, cells to achieve immunomodulation or for other specific therapeutic interventions. Cells are treated by combining the cells with SDC2, treating the cells with an antibody or fragment thereof that binds SDC2 or modulating expression or activity of SDC2 by the cells. Cells or tissue are derived from treated cells for therapeutic uses based on their immunomodulatory or other therapeutic properties.