The paper "New Reference Intervals for Thyrotropin and Thyroid hormones Based on National Academy of Clinical Biochemistry Criteria and Regular Ultrasonography of the Thyroid" by Kratzsch, J. et al., published in Clinical Chemistry  (2005) 51, 8. is a tremendous example of what we need to do in order to reach a real and more comprehencive agrement in terms of the Reference Interval for TSH. The aim of this study was to establish new reference intervals for thyrotropin (TSH) and thyroid hormones based on National Academy of Clinical Biochemistry (NACB) criteria and regular thyroid ultrasonography. They also assessed the effect of potentially confounding factors to modulate the limits of these intervals.