Further analysis of TMPRSS4-mediated signaling in cancer cells suggested that multiple downstream signaling pathways are activated including focal adhesion kinase (FAK) and extracellular signal regulated kinase (ERK) resulting in the downregulation of E-cadherin and induced expression of integrin α5, a critical molecule implicated in tumor cell invasion, migration and tumor progression (18). Here, PTK2 is linked to neoplasm.