CCL2 and glioblastoma: Moreover, glioblastoma cells can produce kynurenine that activates AHR in TAMs; AHR recruits TAMs through CCR2/CCL2, drives the expression of the ectonucleotidase CD39 in TAMs, and plays a synergistic role with CD73 to promote adenosine production, leading to CD8+ T-cell dysfunction (70).