[PsychoPere]

Eve will die if you did not save Maelon's data on the genophage during Mordin's loyalty mission in ME2, because in ME3 Mordin will be attempting to create a cure based on incomplete and faulty information.

As far as I'm aware, the only way to stop Mordin from ascending the Shroud facility to spread the cure is if Wrex died in ME1 and Eve dies in ME3. Without those two alive, apparently you can convince him that the krogan cannot (or should not?) be saved, and he will join the Crucible project as a War Asset. This is my understanding based on what I've read online; I haven't been in a position to confirm it first-hand.