Five studies focused on low-value screening services (e.g., inappropriate PSA-based prostate cancer screening among men aged 75 and over) [32, 35, 39, 40, 43], two studies focused on de-implementing low-value diagnostic tests (e.g., ordering of diagnostic markers) [33, 38], and five studies focused on de-implementing low-value treatment procedures (e.g., inappropriate use of peripheral intravenous and urinary catheters) [34, 36, 37, 41, 42]. The gene discussed is KLK3; the disease is prostate cancer.