CHI3L1 and neoplasm: Translating these in vitro observations to our preclinical TNBC model, dual color immunohistochemistry for the LEC marker lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1) and the TAM marker F4/80 on primary tumor sections from 4T1 tumor-bearing mice further demonstrated the CHI3L1-mediated stimulation on lymphatic vessel integration of macrophages (Fig. 10G).