MEIS1 and leukemia: The reduced responsiveness of the two resulting pools SM6p2 and SM6p3 to CCI-006 was similar in nature to that of the intrinsically unresponsive MLL-r leukemia cells, as exemplified by the absence of apoptosis induction, stable protein levels of MLL gene targets HOXA9, MEIS1, and CMYC, unchanged polysomal profiles and unchanged levels of p-eIF2α and p-JNK upon treatment with CCI-006 (Supplementary Figure 2a–d).