Highlights 19• Computational modelling of human (patho)physiology is advancing rapidly, often using and 20 extrapolating experimental findings from preclinical disease models. 21• The lack of in silico models to support in vivo modelling in mice is a missing link in current 22approaches to study complex, chronic diseases. 23• The development of mechanistic computational models to simulate disease in mice can boost 24 the discovery of novel therapeutic interventions. 25• The 'Digital Mouse' is proposed as a framework to implement this ambition. The 26 development of a Digital Mouse Frailty Index (DM:FI) to study aging and age-related 27 diseases is provided as an example. 28
29Abstract 30 Computational models can be used to study the mechanistic phenomena of disease. Current 31 mechanistic computer simulation models mainly focus on (patho)physiology in humans. However, 32often data and experimental findings from preclinical studies are used as input to develop such 33 models. Biological processes underlying age-related chronic diseases are studied in animal models. 34The translation of these observations to clinical applications is not trivial. As part of a group of 35 international scientists working in the COST Action network MouseAGE, we argue that in order to 36 boost the translation of pre-clinical research we need to develop accurate in silico counterparts of the 37 in vivo animal models. The Digital Mouse is proposed as framework to support the development of 38 evidence-based medicine, for example to develop geroprotectors, which are drugs that target 39 fundamental mechanisms of ageing. 40 41 Keywords: 42 regulatory decision-making, computational modelling, in silico pre-clinical trial, mouse models, aging, 43 digital twin, geroprotectors, frailty 44 45 2 46