The long-overlooked mummy of an obese woman, who likely suffered from diabetes and liver cancer, has been identified as Queen Hatshepsut, the most powerful female pharaoh to rule ancient Egypt. A single tooth was key to solving one of the greatest mysteries of ancient Egypt, Zahi Hawass, the country's antiquities chief, said Wednesday. If fully confirmed, DNA tests are still ongoing, the discovery could be the most significant find since archeologists discovered King Tutankhamun's tomb in 1922, experts say. Hatshepsut ruled for 20 years in the 15th Century B.C., dressing like a man and wearing a fake beard. A monumental builder, she wielded more power than two other famous ancient Egyptian women, Cleopatra and Nefertiti, who unlike her never took on the title of pharoah. But when she died and her rule in the 18th Dynasty ended, all traces of her mysteriously disappeared, including her mummy. In 1903, a mummy was found lying on the ground next to the sarcophagus holding the mummy of the queen's wet nurse in a tomb in Egypt's Valley of Kings burial ground in Luxor. For decades, that mummy was left unidentified and remained in the tomb because it was thought to be insignificant.