CD68 and amyotrophic lateral sclerosis: To identify microglial phenotypes enriched in ALS cases, microglia from control, stage 1–3 ALS, and stage 4 ALS cases were clustered based on the single cell CD68, HLA-DR, and Iba1 average intensities, and morphological measures (cell body area, process number, total outgrowth, and branch number).