PTGER4 and neoplasm: Because of tumor heterogeneity, it is likely that combination of different epigenetic markers improves the diagnostic capability, although this was not the case in our study when combining TMPRSS4 and SHOX2. A report combining SHOX2 and PTEGR4 (Prostaglandin E receptor 4) in plasma using several cohorts of patients obtained AUROC curves between 0.88 and 0.98 [30].