Analyzing the top most differentially expressed genes (FDR corrected p-value < 0.1) between these subpopulations, a clear activation signature appeared in the early, dry AMD-enriched cluster, including APOE, TYROBP, and SPP1 (Fig. 3D), genes known to play a role in neurodegeneration7. This evidence concerns the gene SPP1 and dry age related macular degeneration.