The boundaries of normal kidney tissue for biomedical research.

Purpose of review: In this review, we highlight the importance of understanding the inherent biological variability in normal kidney, or healthy reference tissue, to establish an accurate reference point for biomedical research. We explore this and the advantages and limitations of various sources of healthy reference tissue suitable for structural and omics-level studies.

Recent findings: Several large consortia are employing omic technologies for diseased and normal kidney tissue, underscoring the importance of utilizing healthy reference tissue in these studies. Emerging approaches, such as artificial intelligence and multiomic analyses, are expanding our understanding of structural and molecular heterogeneity in healthy reference kidney tissue and uncovering new insights.

Summary: Biological variability in healthy reference tissue at the functional, structural, and molecular level is complex and remains an active area of study. Thoughtful selection of healthy reference tissue sources is critical, providing the greatest potential for producing high-quality research outcomes.