TLR4 and neoplasm: In the in vitro experiments which recreated the tumor microenvironment we used specific inhibitors for these paracrine factors, to reverse the specific functions identified: a novel antagonistic peptide—PEG-LPrA2—as a leptin signaling inhibitor which significantly delayed onset and decreased progression of mammary cancer in mice [29], or specific inhibitors for CCL2 and TLR4.