TRIB2 and T-cell acute lymphoblastic leukemia: Like Drosophila Trbl, Trib2 protein requires an intact kinase domain to poly-ubiquitinate CDC25 isoforms and, consistent with the notion that Trib2 controls the cell cycle, Trib2 levels oscillate to establish a G1/M gate in mitotically synchronized T-cell acute lymphoblastic leukemia (T-ALL) cells.