BTK and hepatocellular carcinoma: The TEC kinase family constitutes the second largest family of nonreceptor tyrosine kinases including the five members Bruton’s tyrosine kinase (BTK), interleukin (IL)-2-inducible T-cell kinase (ITK or TSK/EMT), tyrosine kinase expressed in hepatocellular carcinoma (TEC), bone marrow tyrosine kinase on chromosome X (BMX or ETK) and tyrosine-protein kinase (TXK or RLK) [1].