GAB2 and acute myeloid leukemia: Using a single-guide RNA (sgRNA) to target Gab2 (or Rosa26) creates a semi-random “library” of indels at each targeted site, with variable levels of Gab2 inactivation achieved in the 3 copies of Gab2 in each AML cell with +7 (frameshift mutations are the most likely to be deleterious).