BTK and B-cell chronic lymphocytic leukemia: While earlier work reported overexpression of multiple BCR downstream signal mediators including BTK [8], LYN [9] and SYK [10], here, we have detected aberrant expression of CD79a (Figure 1A), BCAP (Figure 1B) and PLCγ2 (Figure 1C) in CLL cells from majority of previously untreated CLL patients independent of their prognostic parameters (Supplementary Table 1) as compared to normal B-cells.