The BCR-ABL oncogene encodes a hybrid protein with potent tyrosine kinase activity. This tyrosine kinase is constitutively active, meaning it is always 'on,' which leads to unregulated cell proliferation and survival. This unchecked cellular growth is a hallmark of cancer, particularly in hematologic malignancies like CML. The BCR-ABL protein disrupts normal cellular signaling pathways, including those that regulate the cell cycle and apoptosis (programmed cell death).
