IL4R and major depressive disorder: At the same time, studies have shown that AST transformed hippocampal microglia from M1 phenotype to M2 phenotype by targeting the IL-4R/JAK1/STAT6 pathway and the ubiquitination modification of STAT6, thereby alleviating perimenopausal depression-like behaviors and cognitive deficits in the mouse model of perimenopausal depression [17].