Immunostaining analysis of the effect of BP on the surface interaction of CD44 and MMP-9 in PC3 cell lines. Confocal microscopy analysis of distribution of CD44 (red) and MMP-9 (green) in PC3 cell lines treated with (+, A' to C') or without (-, A-C) pamidronate is shown. Yellow color indicates colocalization of proteins on the cell surface. The results represent one of three experiments performed. Scale Bar-50 μm.