KLK3 and neoplasm: Neuroendocrine tumour markers should be used in the immunohisto-chemical investigation (e.g. chromogranin, synaptophysin), as well as carcinoma markers (cytokeratins: CK5/6, CK7, CK19, CK20, ACE) and other antibodies depending on the anatomo-clinical presentation (e.g. thyroglobulin, prostate specific antigen (PSA), hormonal receptors) (standard, level of evidence: B2).