The authors acknowledge that the information provided in this Corrigendum does not affect the conclusions of the original publication. Image correction referenced from Haddad et al. (1) Image 3 of the Common Pitfalls in the Interpretation of Endocrine Tests, this publication does not correspond to the hook effect. The figure 1 provided in this document, which is taken from the same reference as above, corresponds to Illustration of the high dose hook effect. The left panel illustrates the non-competitive "sandwich" immunoassay with normal (or elevated within the tolerance of the assay kit) hormone concentration. The right panel illustrates the mechanism of the hook effect with exceedingly high hormone concentration. At the sample that contains remarkably elevated hormone concentration is added to the test tube which contains both capture and signal antibodies. it is both the capture and signal antibodies preventing the formation of the "sandwiches". After the washout phase, only a few "sandwiches" will be left producing a low signal.