While the data regarding the possible association between fertility drugs and invasive ovarian cancer are inconclusive, there is evidence to suggest an association between induction of ovulation and borderline ovarian tumors. The plausibility of these results is heightened by the finding that estrogen receptor expression is a common feature of ovarian borderline tumors. On the other hand, recent data indicate that in contrast to the crucial role of germline mutations in the pathogenesis of invasive ovarian cancer, these mutations play a minor role, if any, in the pathogenesis of borderline ovarian tumors. This evidence suggests that the differences between invasive and borderline ovarian tumors are not based on minor morphological criteria, but that, most probably these represent two different entities, with different clinical behavior, and that borderline tumors might be associated with hormonal factors rather than genetic mutations.