PTK2 and B-cell chronic lymphocytic leukemia: In the same group of patients, the CLL-related proteins cortactin and HS1 (hematopoietic lineage cell-specific protein 1) (27, 28), which can interact with FAK and are involved in cytoskeletal shaping and motility of the tumoral cells, were overexpressed, thus hypothesizing a possible interplay with FAK in CLL.