Iliana joined the Obsidian Order against the wishes of her parents, who wanted her to become an artist, and accepted a deep undercover assignment on Bajor. For this assignment she needed to have her appearance surgically altered to look like a Bajoran and went through mind control techniques that erased her own memories and replaced them with the memories of a Bajoran life.
Because of the resemblance between the two women, Kira Nerys was surgically altered to be Iliana, as part of an Obsidian Order plot in 2371 to expose Legate Ghemor's dissident sympathies.
Although her parents would never see her again, Iliana's father believed she was still on Bajor and kept on looking for her until his death in 2373 on Deep Space 9. However, due to the nature of her mission, locating her, even with the assistance of the Bajoran Provisional Government proved to be difficult. Gul Dukat claimed to know where Iliana was and offered to share the information with Ghemor in exchange for his support to the alliance with the Dominion. Ghemor, however, declined. (DS9: "Second Skin", "Ties of Blood and Water")
Iliana Ghemor was played by Nana Visitor.
In an early draft of the script, it would have been left ambiguous as to whether Kira was actually Iliana Ghemor or not.
In the Star Trek: Deep Space Nine relaunch novels Warpath and Fearful Symmetry, parts of the Iliana's fate are revealed. She was held captive by Dukat for around 15 years, but was able to escape during the last days of the Dominion War. Having back her memories as Iliana, but still also having all memories of Kira, she apparently went mad and started to believe that she was the only Kira Nerys to truly bear this name – and thus started to eliminate all other Kiras, starting with Intendant Kira in the mirror universe.
The mirror version of Iliana appeared in our universe and asked the DS9 crew to help her stop her now-mad counterpart in Fearful Symmetry.
The storyline has been left hanging following the time skip in Star Trek: Destiny.