Cypath reacts to proteins in (cell) receptors, not just cancer cells. Since there are many more receptors in cancer cells, they fluoresce more. This means that the resultant sample is assessed by the technician, sort of like grading a gemstone. The demonstration slides JC showed demonstrated a huge difference but I'm not sure that is always the case. This introduces a human element to the assay, not a game changer but...anyway, as with mammograms, detection can probably be improved with a computer scan and some good software...but still.