KLK3 and cancer: In this study we have used available full blood samples from patients enrolled into a prospective PCa screening pilot study (PROSTAGRAM) [11] (n = 109) as well as n = 38 samples of patients with either an established PCa diagnosis or confirmed cancer-negative controls from Imperial College NHS Trust (Table 2) to determine whether combining Episwitch PCa test with PSA test will increase its diagnostic accuracy.