PRV-1 is embedded in the cell membrane via a GPI anchor.

(A) 293 cells were stably transfected with an expression vector for PRV-1 and subjected to digestion with PIPL-C or left untreated. Cells were stained with a polyclonal antibody against PRV-1 followed by a FITC-conjugated secondary antibody (dark and light solid lines, respectively). As a control, both PIPL-C–treated and untreated cells were stained with the secondary antibody alone (dashed and stippled lines, respectively). FACS analysis was performed in a Becton Dickinson FACS Calibur equipped with a 488-nm laser. (B) Peripheral blood granulocytes were purified from a patient with polycythemia vera (dotted line) and one with PNH (solid line). Cells were stained with a polyclonal antibody against PRV-1 followed by a FITC-conjugated secondary antibody. FACS analysis was performed in a Becton Dickinson FACS Calibur equipped with a 488-nm laser.