To determine whether Dox-induced Jak2 knockdown was sustained in these persistent Eμ-Crlf2/Jak2R683G cells, eBFP2+/GFP+ leukemias harvested from the spleens of mice in Figure 3F were analyzed for expression of dsRed as a surrogate readout for shRNA expression. This evidence concerns the gene JAK2 and leukemia.