KLK4 and cancer: The ProScreen trial is a population-based, randomised multicentre trial that investigates the effectiveness of a novel screening strategy combining PSA, a four-kallikrein panel and MRI on PCa mortality over a 15-year period from randomisation.12 The rationale is to minimise detection of clinically insignificant cancers, while maintaining a high sensitivity for aggressive cancers in order to reduce overdiagnosis without compromising mortality benefits.