GRN and amyotrophic lateral sclerosis: Grn deficiency leads to NF-κB activation in microglia and elevation of TNFα, leading to hyperexcitability of medium spiny neurons and obsessive-compulsive disorder-like behavior.357 Recently, interleukin-18 receptor accessory protein (IL18RAP) 3′ untranslated region (3′UTR) variants were identified as protective factors which reduced the risk of developing ALS fivefold, delayed onset, and therefore the age of death in individuals with ALS.