Although there was no correlation between sFRα levels and % tumour cells expressing FRα or the IHC H score (data not shown), receiver operating characteristic (ROC) curve analysis revealed that the baseline level of circulating sFRα in neo-adjuvant treatment-naive patients was predictive of positive tumour cell membrane expression of FRα (AUC = 0.76, P = 0.007 for predicting tumours with ≥5% positive cells and AUC = 0.84, P = 0.0036 for predicting tumours with ≥50% positive cells; Fig. 4a, right, top and bottom, respectively). This evidence concerns the gene FOLR1 and neoplasm.