Figure 1. A human retina section immunocytochemically labeled for GH and GHR. A: DAPI labeling (blue) shows the position of all nuclei in the section. B: Growth hormone (GH) antiserum (green) labels cells in the ganglion cell layer (GCL). C: GH receptor (GHR) antibodies (red) label cells in the GCL. D: When panels B and C are merged, it is clear that GH and GHR are co-localized in the same cells (yellow). Abbreviations: inner nuclear layer (INL); outer nuclear layer (ONL). Scale bar equals 40 μm.