KLK3 and prostate cancer: Currently, standard disease evaluation recommended by the Prostate Cancer Clinical Trials Working Group 3 (PCWG3) guidelines3 specifies imaging tests and prostate-specific antigen (PSA) assessments: these guidelines now also highlights the need for the evaluation of progressive disease (PD) at established timepoints using liquid biopsies to better characterise disease biology and identify potential predictive molecular biomarkers.