CTSD and posterior cortical atrophy: An early pivotal study about PCa biomarker discovery identified a serum glycoprotein signature comprising ASPN, CTSD, HYOU1 and OLFM4, (from this point on, throughout the text, proteins will be indicated via their gene names to allow a more fluent reading) able to discriminate between BPH and PCa groups with an area under the ROC curve (AUC) of 0.726 [14].