Manufacturers and regulators are pressing to eliminate open manipulations in cell therapy production to reduce contamination risk and scale operations. The article outlines how “open” steps—uncapped vessels, pipetting in biosafety cabinets and other operator-dependent tasks—raise sterility and inspection risks, while “closed” single‑use assemblies, sterile connectors and automated transfers validate sterile boundaries and reduce human variability. The piece cites EU GMP Annex 1:2022 and FDA aseptic processing guidance as drivers of this shift and explains how closure improves GMP compliance, inspection readiness, and tech transfer. It also describes practical measures—aseptic tube welds, pre‑sterilized manifolds, and automation—and quantifies operational burdens tied to open workflows such as cleanroom occupancy and skilled‑staff requirements. For industry readers, the story frames closure as both a regulatory imperative and a business lever: it enables autologous scale‑out and allogeneic scale‑up by cutting operator time, environmental monitoring needs, and cross‑batch risk. Technical teams and CDMOs should prioritize validated sterile transfer technologies and automation during process development and facility design.