CTSB and neoplasm: The binding of uPA to uPAR also mediates the signal transduction to promote cathepsin B and 92 kDa collagenase expression; to cause non-receptor protein tyrosine kinase phosphorylation of keratin and src family and the activation of the Jak/Stat pathway; and to regulate tumor cell proliferation, differentiation, movement and angiogenesis [17-20].