KLRK1 and acute lymphoblastic leukemia: Similarly, expression of NKG2D-Ligands was prominent in all tested T-ALL cell lines (KOPT-K1, DND-41, HPB-ALL, Jurkat), whereas NKG2D-ligands were detectable at lower levels in 5 of 6 tested primary T-ALL samples (Figures 3B, F), but not in the control cell line B16 (Figure 3C).