VWF and neoplasm: Interestingly, when we analyzed tumor sections from our previous in vivo experiments by confocal microscopy, we observed that while tumors in control groups infused with UT or control SP6 CAR T cells were highly vascularized and stained positive for the endothelial marker vWF, the p32 CAR T cell treated mice showed significantly less blood vessels in the tumors (Fig. 5e and quantification by ImageJ in Fig. 5e).