ABL1 is a cytoplasmic and nuclear non-receptor tyrosine kinase, which contains Src homogy 2 (SH2) and SH3 domains, a DNA-binding domain, and an actin binding and bundling domain.
ABL1 is involved in actin remodelling, cell adhesion and motility, differentiation, DNA damage and immune responses.
ABL1 is a proto-oncogene; its activity is negatively regulated by the SH3 domain. Deletion of SH3 turns it into an oncogene. Several chromosome translocations activate ABL1 in hematopoietic malignancies (e.g. chronic myeloid leukemia).