In the future, a comprehensive understanding of the KLF4 signaling and its molecular mechanisms during precancerous lesion formation in various tissues will not only help to identify and define whether KLF4 is a “tumor suppressor” or a “tumor promoter,” but also serve as a basis for designing appropriate and effective intervention strategies against PDA and even the other tumors. The gene discussed is KLF4; the disease is Patent ductus arteriosus.