WFDC2 and ductal breast carcinoma in situ: In addition, serum HE4 concentrations did not show a significant difference between low and high mRNA/protein expression in DCIS tissues (39.9 ± 12.7 pmol/L vs. 38.9 ± 10.2 pmol/L, p = 0.788, for mRNA; 39.8 ± 13.4 pmol/L vs. 39.1 ± 9.1 pmol/L, p = 0.838, for protein).