Jack Schlossberg, the grandson of former US President John F. Kennedy, has spoken publicly for the first time about the death of his older sister Tatiana, describing her as his "best friend". Tatiana Schlossberg died in December 2025 at the age of 35 after being diagnosed with acute myeloid leukaemia, an aggressive form of blood cancer, with a mutation called Inversion 3.
In an interview with Vanity Fair, Mr Schlossberg, 33, who is running for Congress in New York's 12th District, said he does not think he will ever fully process his grief. "The world will never be the same for me, not only since she passed away, but since she was diagnosed with cancer about two years ago," he said. He added that her death has motivated him to "make the most out of my precious life" and to fund cures for cancer.
Tatiana Schlossberg revealed her diagnosis in a New Yorker essay published on 22 November 2025, the 62nd anniversary of her grandfather's assassination. She had been diagnosed in May 2024, after the birth of her second child, Josephine. She underwent chemotherapy and received a stem cell transplant from her sister Rose, which initially put her into remission, but the cancer returned.
Mr Schlossberg, the son of Caroline Kennedy and Edwin Schlossberg, said his sister supported his congressional campaign before her death. "The last thing that she said to me was, 'You better win,'" he recalled in a separate interview with CBS Sunday Morning in March. He is determined to honour her by winning the election.
The JFK Library Foundation announced Tatiana's death in a statement in December 2025. She is survived by her husband George Moran and their two children, Edwin and Josephine.
