ARG1 and breast cancer: Lactate-induced TAM polarization and its pro-tumorigenic effects in breast cancer has been attributed to TAM-specific extracellular signal-regulated kinase (ERK)/STAT3 activation, stimulated expression of vascular endothelial growth factor (VEGF) and arginase-1 (ARG1), and stabilization of HIF-1a (91, 121, 122).