Since the gastric tumors that form in gp130Y757F mice are exquisitely sensitive to the inhibition of IL-11 signaling [15], we systemically treated age-matched mice with an anti-IL-11R monoclonal antibody (CSL-4E5) [20] or IL-11 Mutein-PEG [15] (a recombinant protein that is a potent IL-11 signaling antagonist; Figure 3A). Here, IL11 is linked to gastric neoplasm.