CX3CR1 and glioblastoma: Increased monocyte infiltration as a result of Cx3cr1 loss in our GBM model is further supported by a study showing formation of leaky and immature microvessels lacking CX3CR1-positive smooth muscle-like cells, extracellular collagen, and basement membrane laminin in Cx3cr1GFP/GFP but not in Cx3cr1GFP/+ mice, when matrigel plugs were implanted [39].