KLK3 and pachyonychia congenita: There has been significant improvement in the diagnosis of early stage PCs by using a combination of screening tests including digital rectal examination, the measurement of serum prostate-specific antigen (PSA) in blood, histological analyses of the expression levels of PC-specific biomarkers in transrectal ultrasound-guided needle biopsy of prostatic tissues and imaging and genetic tests [6], [7], [62]–[65].