Also, the overlap of the confidence intervals for the ROC AUC accuracy values of the FE marker for ALCAM, calpastatin, PF4, Properdin and TFPI and their corresponding urine protein biomarkers raises the need for further validation of these novel metrics in independent cohorts and larger sample sizes, to ascertain if the FE ratios continue to show improved potential to distinguish active LN from inactive disease, compared to the corresponding urine proteins. This evidence concerns the gene PF4 and lobular neoplasia.