Reference intervals are one of the most commonly used estimates in laboratory medicine. While guidelines and recommendations for analytical, design, and statistical considerations are currently available, several challenges, limitations and methodological gaps still exist. This is particularly true for the pediatric population, where data on healthy children is often limited. In this talk, I will first provide a brief overview of reference intervals and curves, including most commonly used methods to estimate reference intervals and reference curves. I will present existing challenges, limitations, and methodological gaps. I will then discuss our ongoing study aimed at addressing these limitations and gaps.