However, the mean level of cortactin that was phosphorylated at Y421 (pCortactin) and the ratio of pCortactin/cortactin were significantly higher in ROR1Pos CLL (n = 13) than in ROR1Neg CLL cells (n = 11) (P < 0.001) (Fig. 1a, b). This evidence concerns the gene CTTN and B-cell chronic lymphocytic leukemia.