Taken together, we conclude that TNF-α-induced enhancement of breast cancer cell migration is accompanied by increased concentrations of proteases that are directly (MT1-MMP, CD26 and FAP-α) and indirectly (MMP9 and MMP2) associated with the cellular membrane in lipid rafts through activation of the MAPK/ERK signaling pathway. This evidence concerns the gene DPP4 and breast cancer.