PTK2 and hematopoietic and lymphoid cell neoplasm: Studies have shown that FAK signaling pathway is involved in migration and adhesion in human hematological cancers [30, 31], and the integrin expressed on the cell membrane, such as integrin-β4 (ITGB4), VLA-4 or VLA-5, serves as a critical transducer leading to the activation of FAK signaling [15, 32, 33].