We determined the expression of PDI proteins in a panel of non-ovarian cancer cells lines from colon (HT29), pancreatic (MIA PaCa-2 and Panc-1) and breast (MDA-MB-231, MDA-MB-468 and T47D) (Figure 1C, Supplementary Figure 3) for comparison to ovarian cancer cells. This evidence concerns the gene P4HB and ovarian carcinoma.