Parallel Bio is a private biotechnology company based in Cambridge, Massachusetts, founded in 2021 by immunology and bioengineering experts Robert DiFazio and Juliana Hilliard. They focus on human-first drug discovery, using AI-powered, 3D immune organoids—miniature, lymph-node-like tissues—to model the human immune system at scale. Their flagship platform, "Clinical Trial in a Dish," allows pharmaceutical and biotech partners to test immunotherapies and vaccines early on diverse, human-derived tissues, bypassing animal models and aiming to reduce drug development costs, timelines, and failure rates.