Perplexity research agent cited retracted paper as primary evidence in medical report

A clinical research team used a Perplexity-powered agent to compile a literature review on a new treatment protocol. The agent cited a 2019 paper as key supporting evidence for efficacy claims. The paper had been retracted in 2022 due to data fabrication, but Perplexity's index had not been updated to reflect the retraction. The literature review was included in a grant application submitted to NIH. The NIH review panel flagged the retracted citation, which called into question the entire application's rigor. The grant was denied and the team lost 6 months of work.