Artificial intelligence and machine learning (ML) are increasingly applied to the study of patients with RCC [1]. Advanced techniques, such as neural networks or random forests, can be used to analyse a vast amount of clinical data to uncover specific prognostic features that may not be detectable with traditional statistical methods. However, despite some promising results, recent studies show that the benefits of ML are not ubiquitous, especially when deployed on imperfect and non-granular datasets [2].In this issue of the BJUI, Boulenger de Hauteclocque employ data from the French multi-institutional kidney cancer database UroCCR (ClinicalTrials.gov Identifier: NCT03293563), to investigate the ability of seven ML algorithms to predict pT3a upstaging in a cohort of patients who underwent surgery for cT1/cT2a RCC. Using supervised ML algorithms, they reported a prediction accuracy (measured by the area under the receiver-operating curve) of 0.77 for their best model [3]. While the results are intriguing, the design of the study raises questions that should be considered by clinicians when interpreting the results.