Other studies highlighted that TLR-4 increased the rate of lung metastasis in inflamed mice through the upregulation of C–C chemokine receptor type 2 (CCR2) expression [22] and proved that the TLR4/Myd88/NF-κB/MMP2 axis plays a crucial role in cancer metastasis [23, 24]. This evidence concerns the gene MMP2 and cancer.