NTRK1 and hepatocellular carcinoma: Since the PAR1-selective agonist peptide, TFLLRN-NH2, and the PAR4-selective agonist peptide, AYPGKV-NH2, can also induce activation of the PDGFR in Hep3B liver carcinoma cells, a coordinated receptor tyrosine kinase signalling of the PARs 1, 2 and 4 in liver carcinoma cells may be suggested [53].