CHI3L1 and neoplasm: The murine anti-CHI3L1 antibody mAY was shown to inhibit angiogenesis in an in vitro tumor model by interrupting angiogenic signaling cascades through the vascular endothelial growth factor receptor 2 (VEGFR 2) and the MAPK/Erk pathway.111 In addition, a reduction of radiotherapy resistance mechanisms mediated by PI3K/Akt was observed after mAY application.