RT Journal Article SR Electronic T1 Lights on HBME-1: the elusive biomarker in thyroid cancer pathology JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP jclinpath-2022-208248 DO 10.1136/jclinpath-2022-208248 A1 Giorgio Cazzaniga A1 Davide Seminati A1 Andrew Smith A1 Isabella Piga A1 Giulia Capitoli A1 Mattia Garancini A1 Vincenzo L'Imperio A1 Nicola Fusco A1 Fabio Pagni YR 2022 UL http://jcp.bmj.com/content/early/2022/04/20/jclinpath-2022-208248.abstract AB Among the different ancillary immunohistochemical tools that pathologists may employ in thyroid nodules, the so-called Hector Battifora’s ‘MEsothelioma’ 1 (HBME-1) staining is one of the most fascinating, since its real identity is currently unknown. In the present review, the different clinical applications of HBME-1 are analysed, with main emphasis on its role in thyroid pathology with overview on less impactful fields, such as haematopathology or mesothelial lesions. Different acceptable or good diagnostic performances were recorded for HBME-1 in thyroid pathology, being used in routine practice as one of the best tools to screen thyroid malignancy both in terms of sensitivity and specificity. From a speculative point of view, after many attempts to hunt the cryptic target antigen of this antibody, its identity still remains elusive. In this setting, the application of high-throughput technologies (mainly in situ proteomics) may be the exact route to improve the knowledge about the pathophysiology of HBME-1 and to finally unveil its true identity.