Consistent with the earlier reports, the sphere-forming cells from PANC-1 xenografts (hereafter termed PANC-1 CSLCs) were enriched for cells with surface expression of CD133, a known marker for CSCs/CSLCs of a variety of human cancers including pancreatic cancer (Supplementary Figure S1A) [29, 30] and expressed higher levels of pluripotency markers such as Sox2 and Nanog (Supplementary Figure S1B,), as compared with their differentiated counterparts. Here, SOX2 is linked to cancer.