For example, the kinases LYN,18 LCK,54 SYK,20 ZAP-709, BTK24 and PKCβ,55 the adaptor protein TCL156 and the phosphatase PTPN2257 are all overexpressed in CLL cells, whereas the adaptor protein SHC58 and the phosphatase PHLPP159 are expressed at markedly reduced levels. Here, SYK is linked to B-cell chronic lymphocytic leukemia.