CD59 and posterior cortical atrophy: Immunofluorescent staining of PC3 cells with both the Siglec-9-Fc–FITC conjugated antibody and anti-CD59 antibody conjugated with PE confirmed cell surface colocalization of CD59 and Siglec-9 binding (Figure 6M), supporting the notion that CD59 is a potential Siglec-9 ligand in PCa cells.