Iluzanebart, a human monoclonal IgG1 antibody, functions as an agonist antibody for human TREM2 (hTREM2), thereby enhancing the survival and overall function of microglia through the activation of the TREM2 signaling pathway. Iluzanebart provides compensation for the loss of CSF1R function, and it can be employed as a research agent for adult-onset leukoencephalopathy associated with CSF1R (colony stimulating factor 1 receptor) (CSF1R-ALSP), thereby providing opportunities to model microglial dysfunction in neurodegenerative disorders.