Industrial Genotoxicology Group: 38th Annual Meeting Report

Abstract The 38th annual meeting of the Industrial Genotoxicology Group (IGG) was held at Lhasa Limited, Leeds, UK on 2 December 2025, and focussed on the assessment of biological relevance in genotoxicity testing and the appropriate use of historical negative control data. Presentations covered updates on assay development, practical challenges in interpreting borderline or equivocal results, and evolving regulatory expectations across OECD and International Council for Harmonisation (ICH) frameworks. The meeting also featured the New Investigator Technical Award and the Lhasa Young Scientist Memorial Award, recognising innovative technical contributions across the field. Through scientific sessions and an interactive workshop, attendees explored case studies illustrating how statistical significance, biological relevance, and quality of historical negative control (HNC) data intersect in regulatory decision-making. Key themes included the stability and interpretation of historical control data ranges, the application of statistical process control, and the complexities of assigning confidence to negative findings. The meeting highlighted the continued need for expert judgement when assessing genotoxic outcomes and the importance of transparent, high-quality data to support regulatory conclusions.