ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: As yet, endogenous CD4+ and CD8+ T cell responses directed against leukemia-specific antigens (LSA) and leukemia-associated antigens have been detected in chronic phase CML patients (14–17) — particularly LSA derived from the junctional region of BCR-ABL1, which represent CML-specific neo-antigens.