Dr. Charlene McGowan worked for CalTech until she was fired for drugs she was using to manage the stress of her gender transition. She got a job with Kingpin in New York running a black market MGH lab. She attempted to pivot the lab to making black market hormone lab to help the transgender community. Unfortunately, Daredevil raided the lab, and McGown was arrested. She was recruited from prison by General Fortean for his US Hulk Operations.
Dr. McGowan made her debut in The Immortal Hulk #6 by Al Ewing and Lee Garbett.
Major Story Arcs
US Hulk Operations
McGowan was Fortean's head of research into gamma mutates. She was responsible for grafting Rick Jones to the Abomination corpse. She was also responsible for trying to lessen Del Frye's pain, despite Fortean just wanting to use him as a weapon. For this, Rick Jones spared her life when he returned to Shadow Base for revenge.
When Fortean was grafted to the Abomination corpse, she relieved him of his leadership. This proved to Hulk that she was worth working with, when he took control of the Hulk Operations from her. She was especially helpful operating Shadow Base's translocator for when Hulk when on his various missions.
When the Leader attacked Shadow Base, McGowan sought out Jackie McGee, a journalist getting famous for her coverage of the Hulk. Jackie revealed to McGowan that she was developing gamma mutations, so the two of them sought out Gamma Flight.