To learn more about the way the HER2-CAR CMV-T cells are working and how long they last in the body, blood will be taken on the day of the T-cell infusion, before, 1 hour and 4 hours after the T-cell infusion, 1, 2, 4 and 6 weeks after the T-cell infusion and every 3 months for 1 year, every 6 months for 4 years, then yearly for a total of 15 years.