First we show that LIN28B and Sox6 expression is mutually exclusive in mouse and human erythropoiesis, which represents a well-defined model of development (Figs. 1 and 2) as well in several cancer cells (Figs. 3, 4 and Supplementary Figs. 5 and 6), in particular neuroblastoma and hepatocarcinoma cell lines. This evidence concerns the gene LIN28B and neuroblastoma.