While we observed consistent U5 snRNP200 surface expression on B220+ B lymphocytes (Fig. 8a and Extended Data Fig. 3), as seen in humans, we observed a range of U5 snRNP200 surface expression on malignant myeloid cells across a number of myeloid leukemia mouse models (Fig. 8a). This evidence concerns the gene PTPRC and myeloid leukemia.