Page 4: Research news on Biological Variation, Individual

Individual biological variation refers to the naturally occurring differences in measurable biological characteristics among individuals of the same species, arising from the interplay of genetic, epigenetic, developmental, and environmental factors. It encompasses intra-individual (within-person, over time) and inter-individual (between-person) variability in parameters such as gene expression, metabolic activity, immune responses, and physiological biomarkers. This process underlies differential susceptibility to disease, heterogeneity in drug response, and variation in phenotypic traits. In research and clinical laboratory science, individual biological variation is quantitatively characterized to distinguish physiological fluctuation from pathological change and to establish reference change values and personalized reference intervals.