TLR2 and colorectal carcinoma: It was demonstrated that after in-vitro GM-CSF stimulation but not with M-CSF, GM-CSF down-regulates major recognition receptors on human monocytes, including TLR1, TLR2, and TLR4, impeding proinflammatory cytokine production in the TLR axis, resulting in the peripheral blood monocytes exert cytostatic impact on CRC cells [13].