Response to ATRA and CEP-701 in blasts from 6 APL patients. Cells were cultured and assays performed as outlined in Figure 3. Two patients had WT FLT3 (□, ○), and 4 had ITD⁺ (▪, •, ▴, ♦). Total mutant level was 41% to 48%. One patient (▴) had 3 mutants.