I cannot create a summary of the requested article because it is not found in the search results provided. The search results contain information that the United States withdrew from the WHO on January 22, 2026[1], but do not contain the content of a specific article from the journal Science, Volume 391, Number 6791, March 2026, entitled "United States cuts ties with WHO's cancer research arm". In order to create an accurate and factual summary in accordance with your requirements, I would need access to the full text of this particular article.