VEGFA and neoplasm: For example, hypoxia augments the immunosuppressive ability of TAMs,14 while lactic acid induces tissue remodelling though expression of vascular endothelial growth factor (VEGF) and arginase I.15 Whether acidic pH, as an independent entity from lactate,16 alters macrophage polarisation within tumours is not clear, hence, we sought to investigate the impact of tumour acidosis on the phenotypic characteristics of macrophages in vitro using zwitterionic organic buffering agents.