Given that cancer cells and ESCs share many cellular and molecular features, several core pluripotency genes, such as Oct4, Sox2, Klf4 and Nanog, are highly expressed in various types of human cancers, and some “NOS target gene sets” are enriched in high-grade tumours47,58.It could be speculated that other gene modules may reflect stemness in cancer. The gene discussed is KLF4; the disease is cancer.