The article by Dobrijevic et al1 in this issue of AJKD presents a rigorous analysis using Mendelian randomization (MR), which has particular strength to estimate causal effects, to explore the potential causal links between kidney function and cancer risk. By leveraging large-scale, well-characterized datasets from reputable sources such as the CKDGen consortium and the UK Biobank, the authors have performed a reliable analysis. The use of both estimated glomerular filtration rate and urine albumin-creatinine ratio as markers of kidney function provides a nuanced understanding of the relationship between kidney health and cancer risk.