PTK2 and hepatocellular carcinoma: (46) found that bone marrow endothelial cells upregulated CX3CL1/CX3CR1 expression in HCC spinal metastases by secreting soluble CX3CL1, which was involved in Src/protein tyrosine kinase 2 (PTK2) activation of Hep3B and MHCC97H cells migration and invasion into the spine.