PSE isn't a general category of test; it's a proprietary screening approach from one specific company that combines the standard PSA test with epigenetic testing (the "E") to reduce the rate of false positives.

In other words, if your PSA indicates you *might* have active prostate cancer, they claim their extra epigenetic testing can refine that to "yeah, it's likely" or "no, probably not," and they've collected some test data to back that up.