CD4 and acute lymphoblastic leukemia: Three of the seven T-ALL cell lines (Jurkat, KOPTK1 and RPMI8402) had LMO1 expression levels significantly above those in CD4 T cells with the remainder having undetectable levels of expression (AllSill and CCRF-CEM) or similar levels to those seen in CD4 T cells (Molt4 and Karpas45) (Figure 3b).