To fully elucidate the specificity of SPOA killing CML cells, we examined the effect of SPOA on the proliferation, cell cycle, and apoptosis of 32D cell line, which is a BCR-ABL negative myeloid cell line from C3H mice and the parental cell of 32DP and 32DP T315I. Here, BCR is linked to chronic myelogenous leukemia, BCR-ABL1 positive.