Table 2.

Examples of reported cases of the hook effect for hormone measurements

Analyte	Measured concentration before dilution	Actual concentration after serial dilution	Reference
Prolactin	164.5 ng/mL	26,000 ng/mL (macroadenoma)	Frieze, et al. 2002 [28]
Calcitonin	182 ng/L	450,000 ng/L	Schiettecatte, et al. 2016 [193]
Thyroglobulin	3.8 ng/mL 4.6 ng/mL	207,855 ng/mL 140,462 ng/mL	Hillebrand, et al. 2020 [194]
HCG	Low/normal	5,899,478 mIU/mL (gestational trophoblastic disease)	Cormano, et al. 2015 [195]

Abbreviation: HCG, human chorionic gonadotropin.