Host-cell proteins (HCPs) are major impurities of concern in biomanufacturing. When present in drug formulations, they can reduce efficacy (by compromising product stability), introduce toxicity, and increase a recipient’s risk for long-term immunogenicity. Understanding HCP profiles and integrating effective removal strategies are important parts of developing new biological drugs — to fulfill regulatory guidelines and to ensure patient safety through product quality. HCP populations can be both complex and structurally diverse, and some changes in upstream culture conditions can affect…