PTGES and cancer: Given that lumbrokinase has previously been reported to inhibit the upregulation of COX-2 expression caused by cardiac deficiency, reperfusion injury [37], and COX-2/mPGES-1/PGE2 signaling axis has been reported to be involved in the self-renewal and chemotherapeutic resistance of cancer stem cells [38,39], we speculated that the enhancement of chemosensitivity mediated by lumbrokinase in NSCLC cells might also be achieved by its targeted regulation on COX-2.