Additional Study Information: In this research study, we are looking for Information on how well nivolumab with or without ipilimumab works in combination with TTFields in adult patients with glioblastoma. You will receive the Nivolumab and/or Ipilimumab study treatment until you decide to stop study treatment or your study doctor decides to remove you from the study. This means that you can stay on the study as long as there are no unmanageable risks. After you finish your study treatment, the study doctor will continue to watch you for side effects and follow your condition for 3 years.