SPP1 and amyotrophic lateral sclerosis: Distinct immune markers were found to differentiate FTD from Alzheimer’s disease (AD) and amyotrophic lateral sclerosis (ALS), with GFAP, SPARC, and SPP1 varying between FTD and AD and IL-15, HERV-K, NOD2, and CHIT1 differing between FTD and ALS.