Fig. 4. MDCK cells expressing Fc38-63 were processed as described in the legend to Fig. 3 except the cells were incubated with caveolin 1 antibodies rather than antibodies to furin. The upper panel in each confocal image corresponds to an xy-slice near the middle of the cells, whereas the lower panel corresponds to an xz-slice. Black bars mark the position of the basal membrane. Bars, 10 µm.