PLG and neoplasm: The absolute requirement for the functional assembly of an active uPA/uPAR cell surface template for uPA-mediated plasminogen and subsequent PrAg-U2 activation in vivo was impeccably demonstrated by the complete lack of treatment response in tumor-bearing plg, uPA, and uPAR single-deficient mice challenged with the engineered toxin, as opposed to wild-type mice, which, in contrast, became terminally ill [82,83,209].