In sharp contrast, all transforming Abl variants are exclusively cytoplasmic, such as Bcr-Abl, even though which contains same NLS and NES sequence as c-Abl. It is critical in inducing human chronic myelogenous leckemia (CML).

• 例如BCR-Abl,虽然它具有与c-Abl相同的C端序列和NLS、NES,但它只存在于胞质中,而且胞质中BCR-Abl的组成型活化是导致人类慢性粒细胞白血病(CML)的重要原因。