A guide to reading cellular and animal data without overinterpretation.
The value of a model
A preclinical model isolates a question in a controlled system. Cell lines can examine signalling, while animal models can explore interactions between organs and responses over time. Their value lies in experimental clarity and hypothesis generation.
Internal and external validity
Good randomisation, appropriate controls and blinded assessment strengthen internal validity. External validity concerns how far a result travels beyond the model. Differences in species, biological background and experimental conditions limit generalisation.
Translation is not automatic
A positive preclinical finding is not a human recommendation, and a negative finding does not exclude every other condition. Responsible synthesis states the model, endpoint and uncertainty, and looks for convergence from independent methods before proposing a broader mechanism.