Horizon Discovery Group plc, a cell engineering company, engages in the design, manufacture, and application of gene editing and gene modulation tools in the United Kingdom, the United States, Europe, the Middle East, Africa, the Asia-Pacific, and internationally. The company operates through Screening, Research Reagents, Diagnostics, and BioProduction segments. It provides custom-made and off-the-shelf (OTS) RNAi gene modulation reagents, CRISPR reagents, synthetic SGRNAs, OTS cell models, and custom cell engineering services. The company also offers pooled CRISPR screens; arrayed RNAi and CRISPR screens, drug screens, and immunology assays; and RNAi and CRISPR screening libraries; and human T-Cell CRISPR screening service to meet the requirements of immunology based research in drug discovery. In addition, it provides OTS gene-edited CHO cells and custom CHO cell lines, and custom CHO gene engineering services; and OTS cell-based reference standards, made to order reference standards, and custom cell-based reference standards to evaluate molecular assays on a research use basis. The company serves customers in academic research labs, biopharmaceutical and diagnostics companies, and contract research and manufacturing organizations. It sells its products through direct field sales channel and e-commerce platform. The company has a partnership with the Rutgers, The State University of New Jersey to develop and commercialize base editing, a gene editing technology; strategic collaboration with Mammoth Biosciences to develop CRISPR tools to provide engineered cell lines for the biopharmaceutical industry; and collaboration with St George's University Hospital, London, and the European Molecular Genetics Quality Network to develop reference material for non-invasive prenatal testing. Horizon Discovery Group plc was founded in 2007 and is headquartered in Cambridge, the United Kingdom.