Figure 4. Longitudinal photomicrograph of the capsule retrieved from patient 4, 845 days after implantation showing (A) at lower power, the absence of reactive cells around the capsule and well-preserved chromaffin cells inside the capsule (scale bar = 100 micro meter), and (B) immunostaining with an antibody reactive with tyrosine hydroxylase that shows the presence of positive cells on the cluster periphery (scale bar, 50 micro meter).