One of the best things about Marvel's Infinity Saga box set is the collection of deleted scenes from every Marvel Cinematic Universe film that has been released so far. Not surprisingly, there's an interesting scene from Ant-Man and the Wasp that confirms Hank Pym and Janet van Dyne were partially responsible for creating Ghost.
In the movie, Ava Starr revealed that her father Elihas Starr was fired by Hank but had continued working on an experiment. Unfortunately, it caused an explosion that killed both of Ava's parents and gave her phasing abilities. However, the deleted scene from the Ant-Man sequel tells a completely different story (via Comicbook.com).
The deleted scene features both Hank and Janet working with Elihas on the experiment that ended up changing Ava's life. This means that they both had a hand on creating Ghost in the first place. However, this part of Ava's story was changed in the Ant-Man and the Wasp theatrical cut.
It's unclear why Ava's origin story had to be changed but at least we can rest assured that the character is expected to return in the third Ant-Man movie. There have been speculations that Ghost will manage to control her powers and eventually help Scott Lang and Hope van Dyne in Ant-Man 3.
The Infinity Saga box set also features deleted scenes from Thor: Ragnarok that gives Odin a different death as well as a rare photo of Captain Marvel joining the heroes in Avengers: Age of Ultron. The box set is currently available and retails for $549.99.