In ovarian cancer, there are also conflicting studies: one group has reported an increase in cell proliferation on the OVCAR-3 cell line mediated by P2Y2R (Popper and Batra, 1993), whereas another group has found opposite effects mediated by this receptor in the EFO-21 and EFO-27 cell lines (Schultze-Mosgau et al., 2000). This evidence concerns the gene P2RY2 and ovarian cancer.