LIN28B and cancer: To search for the origin of LIN28B-expressing cancer cells within primary PDAC tumors, we analyzed an independent cohort of 80 resected PDAC tumors for LIN28B RNA expression by RNA in situ hybridization (Supplementary Fig. 7a, Supplementary Table 5) and at the protein level by immunohistochemistry (Supplementary Fig. 7b).