Following flow cytometric isolation of oncogene-expressing AML cells, in vitro 4-OHT treatment resulted in Ube2nC87S recombination and protein expression, as indicated by the thermodynamically stable version of Ube2n (Ub-Ube2n inactive) (Figure 2E and Supplemental Figure 2, A, and B). Here, UBE2N is linked to acute myeloid leukemia.