PTK2 and neoplasm: Based on the results obtained - after induction using high concentrations of the specific anti-HLA-DR monoclonal antibody L243- in vitro in cell lines without in vivo confirmation, it appears that tumor cells growth and aggressiveness may be due to HLA-DR-mediated signaling that induces ILK/AKT (integrin-linked kinase/protein kinase B), FAK/PAX/AKT (focal adhesion kinase (FAK)/paxillin/Protein kinase B) and BRAF/ERK (extracellular signal-related kinases) signaling pathways activation as well as the lipid rafts recruitment of FAK and AKT proteins (22–25).