ERG and Familial prostate cancer: Much like the urine albumin to creatinine ratio (uACR) test used for evaluation of chronic kidney disease, prostate cancer diagnostics that detect RNA will typically utilise the detection of another transcript to generate an expression ratio or to “normalise” the result rather than reporting an absolute quantity, e.g., the ExoDx test detects ERG and PCA3 relative to SPDEF [30].