Tumors send out signals that impair normal blood flow, which makes them hard to treat with every type of cancer treatment, including radiation and chemo-, targeted and immunotherapy. Impaired blood supply creates an environment low in oxygen levels—hypoxia—that causes the tumors to take on aggressive characteristics and become immuno-suppressed. To address this challenge, a team led by researchers at Massachusetts General Hospital (MGH) developed two approaches to repair tumor blood vessels and improve their function. Also, by devising a method to assess the effects of these approaches and testing it in a study published in Clinical Cancer Research, a journal of the American Association for Cancer Research, the investigators found that each approach may help to restore blood flow to enhance chemotherapy’s access to cancer cells and alleviate hypoxia, and combining them may be especially effective.