PTK2 and neoplasm: For instance, when DDR1 binds COLI, the proliferation and invasion of tumor cells are promoted through the activation of FAK-related protein tyrosine kinase 2 (PYK2), which consequently downstream activates the Crk-associated substrate (CAS)/Ras-Proximate-1 (RAP1)/c-Jun N-terminal Kinases (JNK1)/c-Jun cascade.