TREM2 and amyotrophic lateral sclerosis: The genes involved in facilitating the TREM2 signaling pathway (TYROBP, APOE) as well as MS4A and CD33 mRNA levels were significantly increased in ALS patients versus controls: TREM2 (fold change (FC) = 2.948; p-value < 0.0001) (Figure 1), TYROBP (FC = 1.571; p-value < 0.05) (Figure 2A), APOE (FC = 1.298; p-value < 0.05) (Figure 2B), MS4A (FC = 3.912; p-value < 0.001) (Figure 2C) and CD33 (FC = 1.608; p-value < 0.01) (Figure 2D).