TGFB1 and neoplasm: Flow cytometric analysis identified a M1 to M2 polarization of RAW264.7 macrophages co-cultured with 4T1 tumor cells based on their significantly decreased intracellular expression of the M1-related (i.e. pro-inflammatory) cytokine interleukin (IL)-12 and significantly increased intracellular expression of the M2-related (i.e. anti-inflammatory) cytokine transforming growth factor (TGF)-β1 compared to RAW264.7 macrophages that were cultured alone (Fig. 4a).