• Mast cells secrete angiogenic (VEGF-A, CXCL8, and MMP-9) and lymphangiogenic factors (VEGF-C and VEGF-F) • Mast cells secrete IL10→ ↑Treg in draining lymph nodes • Tumor cells secrete TNF-α→ ↑PD-L1 in mast cells via NF-κB pathway. Here, MMP9 is linked to neoplasm.