KLK3 and posterior cortical atrophy: However, in the last few years novel PCa detection assays, such as the 4K score and Prostate Health Index (PHI) which integrate PSA with other biomarkers (Fossati et al., 2015; Parekh et al., 2015), have emerged with the aim of reducing the rates of false positives and the number of unnecessary biopsies (Table 1).