Notably, a soluble variant of TREM2 (sTREM2) detected in cerebrospinal fluid (CSF) and plasma exhibits dynamic concentration changes through the AD continuum, with initial elevations during early symptomatic phases followed by reductions in later stages (Piccio et al., 2008, 2016; Heslegrave et al., 2016; Suárez-Calvet et al., 2016a,b; Zhou W. et al., 2023; Yin T. et al., 2024). This evidence concerns the gene TREM2 and Alzheimer disease.