Jack Schlossberg's world will 'never be the same' after sister Tatiana's death

Jessica Schladebeck, New York Daily News on May 16, 2026

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NEW YORK — Jack Schlossberg may be busy running for Congress in New York — but he hasn’t stopped thinking about his late sister, Tatiana.

“I don’t think I’ll ever process it,” he told Vanity Fair in an interview published Friday. “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.”

Tatiana, the granddaughter of the late President John F. Kennedy and Jacqueline Kennedy Onassis, died this past December, after being diagnosed with acute myeloid leukemia, an aggressive form of blood cancer, with a mutation called Inversion 3. She was 35 years old.

“She was my best friend. We could finish each other’s sentences,” Schlossberg said. “I miss her all the time. Every day I think about her.”

Schlossberg, 33, who’s running for Congress in New York’s 12th District, added her death has pushed him to “do everything I can with every waking moment I have.”

“I realize it could have just as easily been me,” he said, “and I have an obligation to her, not just to myself, to make the most out of my precious life and all that I’ve been given in this life to give back to others and make sure that we can fund cures for the type of cancer that took her life, and for other types of cancer.”

Tatiana revealed her diagnosis in an essay published in The New Yorker in November 2025. She said she learned of her condition in May 2024, shortly after giving birth to her daughter.

“I did not — could not — believe that they were talking about me,” Schlossberg said, recalling the devastating conversation she had with her doctors. “I had swum a mile in the pool the day before, nine months pregnant. I wasn’t sick. I didn’t feel sick. I was actually one of the healthiest people I knew.”