The overall improvement in screening of PCa using the PHI makes sense; the [−2]proPSA measurement is performed through use of a recombinant [−2]proPSA calibrant and an anti [−2]proPSA antibody that exhibits low crossreactivity to free PSA (<0.2%) and other truncated precursor forms of PSA (<2%)26. This evidence concerns the gene KLK3 and posterior cortical atrophy.