The B-chronic lymphocytic leukaemia (B-CLL) MEC-1 cell line and the B-acute lymphocytic leukaemia (B-ALL) Nalm 6 cell line that do not express ROR1 served as negative controls while MEC-1 that was genetically transduced to express the ROR1 gene (human ROR NM_005012.4), namely MEC-ROR1, was a positive control (Figure 1). This evidence concerns the gene ROR1 and B-cell chronic lymphocytic leukemia.