Using the T-ALL cell line, ALL-SIL, which carries a t(10;14) translocation concomitant with high levels of HOX11 expression [3] and the TAL1+ Jurkat T-ALL cell line [34] transfected with the HOX11 cDNA, we observed a similar pattern of HOX11 phosphorylation in T cell lines as was seen in HOX11-expressing NIH 3T3 cells with the additional low mobility band only being detected in cells exposed to mitotic arresting agents (Figure 6A). The gene discussed is TAL1; the disease is acute lymphoblastic leukemia.