SPP1 and glioblastoma: Differentially expressed gene analysis identified SPP1 and CCL2 as significantly upregulated genes in those TREM2+ LAM-like cells derived from tumor samples compared to those derived from adjacent liver tissues (Figure 2G), in line with reports stating that SPP1 is secreted by infiltrating macrophages and stimulates angiogenesis (33) and that CCL2 participates in tumor-mediated immunosuppression by recruiting immunosuppressive Treg cells and myeloid-derived suppressor cells into the glioblastoma microenvironment (34).