Analysis of the significantly modified genes found in NPC1, AD, and ALS transcriptomes together with the MLIV microglia transcriptome revealed 100 genes that were significantly modified and followed the same expression pattern in all four disease models (Fig. 4b, c; Additional file 4: Figure S4); 13 genes were downregulated and 87 were upregulated among these 100 genes. The gene discussed is NPC1; the disease is Alzheimer disease.