Immunohistochemistry for the four most highly up-regulated transcripts in zG. Each panel shows a representative image of immunohistochemistry for CYP11B2 (A), RGS4 (B), SMOC2 (C), and MIA1 (D). These figures show clear histological zonation of zG (g), zF (f), zona reticularis (r), and medulla (m) according to nuclear staining using hematoxylin. Arrowheads in D indicate a subset of fasciculata cells that are stained with MIA1. Scale bar, 100 μm.