To examine the effect of Bcr-Abl on CML cells after nucleation, we used immunofluorescence assay to observe the changes of the nuclear morphological structure of K562 cells treated with HSP90 inhibitor 17AAG for 6 h and 12 h (Fig. 4a). The gene discussed is HSP90AA1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.