KITLG and neoplasm: Under hypoxia and acidosis conditions, MCs release pro-angiogenic mediators such as VEGF-A/VEGF-A/CXCL8/endothelin-1 and VEGF-C/D pro-lymphangiogenic factors (37, –, 39) to rebuild the tumor vasculature network and accelerate the metastatic progression, which may be associated with stem cell factors (SCF).