[rflrob]

That assumes that what causes the false positive is some kind of analytical noise in the test. The bigger concern is biological noise that would persist if you tested the patient again.

It might still be useful to know you have weird protease activity that isn’t cancer derived, but the more of these tests we do, the more likely it is that for every person, there’ll be at least one non-cancer oddity that looks like cancer signal for at least some test.