KITLG and neoplasm: Furthermore, mast cell tumour‐promoting potential is augmented through costimulation with tumour‐derived SCF and Toll‐like receptor 4 (TLR4) ligand, inhibiting mast cell degranulation, but triggering their production and secretion of vascular endothelial growth factor (VEGF) and interleukin‐10 (IL‐10).