In direct ELISAs and Western blots, less than 1% cross-reactivity with recombinant mouse (rm) B7-1, rmB7-2, rmB7-H1, rmB7-H2, rmB7-H3, and rmPD-L2 is observed. Reconstitute at 0.2 mg/mL in sterile PBS. B7-H4 (B7x, VTCN1) a costimulatory protein which is