When we used a signature related to the malignant potential of ovarian tumors (Ouellet et al. 2005) to cluster our serous/undifferentiated cancer samples, we obtained a clustering pattern almost identical like with our 151-probe set signature that was entirely due to the expression patterns of, COL11A1 and MMP2, the only two genes common to both signatures. Here, MMP2 is linked to ovarian neoplasm.