The later study showed that loss of imprinting of Igf2 was not a prominent mechanism for Igf2 over-expression in serous epithelial tumors, but high frequency of epigenetic alterations at the Igf2/H19 domain was actually more frequently observed in benign tumors, indicating that epigenetic changes of Igf2/H19 may be an early indicator of ovarian cancer [51]. This evidence concerns the gene H19 and ovarian cancer.