Differences in number were assessed regarding IBA1-immunoreactive cells; increased numbers of monocyte derived macrophages/microglia (543.1 ± 36.2 cells/mm2 in ALS versus 312.6 ± 19.3 cells/mm2 in controls), in addition to high predominance of amoeboid cells, were found in the pyramidal tracts of the spinal cord in ALS (Figures 2(d) and 2(e)). Here, AIF1 is linked to amyotrophic lateral sclerosis.