ABL2 (or ARG) is a nonreceptor cytoplasmic tyrosine kinase which is closely related to but distinct from ABL1. The similarity of ABL1 and ABL2 includes the tyrosine kinase domains and extends amino-terminal to include the SH2 and SH3 domains. ABL2 is involved in translocation with the ETV6 gene in human leukemia and has an altered expression in several human carcinomas (1). Two isoforms of ABL2 with different N-termini (1A and 1B) have been identified. The C-terminal domain of ABL2 contains two F-actin-binding sequences that perform a number of actions related to cell morphology and motility by interacting with actin filaments (2).