The re-analysis of a population of the ITGA4/CD49d expressing cells (the integrin alpha 4 was previously reported to specifically mark CNS-invading macrophages [59]) demonstrated that glioma infiltrating monocytes and macrophages show a gene expression trajectory consistent with a monocyte-to-macrophage transition in the TME [69]. The gene discussed is ITGA4; the disease is central nervous system cancer.