Zohn confirmed that his Hodgkin's lymphoma had recurred, but because of a new form of chemotherapy he has been able to train for the marathon without issue.
"[I had] no hesitation whatsoever that I would still run in the marathon," Zohn told People. "But a lot of other people did."
Zohn credits a new form of 'smart chemotherapy' - which targets only cancerous cells - with enabling him to compete despite his diagnosis.
"If I was on the other type of chemo I wouldn't be able to run," Zohn explained. "Everyone who is running has a cause and I'm living proof that it works.
"Finishing for me is going to be a big deal. I'm going to work, shake hands, give high-fives and kiss babies."
Zohn added: "I"m going to have the time of my life."
Zohn is running this weekend's New York City Marathon to raise money for HIV/AIDS prevention.
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