Abstract The high mobility group protein 2 (HMGA2) is an essential component of the enhanceosome. It can attach to AT-rich binding sites in the DNA minor groove, affect the conformation of the DNA, and thereby modify the transcription of numerous genes. HMGA2 is preferentially expressed during organogenesis. Aberrant expression of HMGA2 in adult tissues is commonly associated with tumor formation and cancer aggressiveness. Accordingly, HMGA2 represents a potential drug target. To better comprehend the role of HMGA2 expression in cancer, a tissue microarray containing 8,344 samples from 115 different tumor entities and 608 samples of 76 different normal tissue types was analyzed. In normal tissues, a strong nuclear HMGA2 staining was limited to few cell types from the amnion, placenta, seminal vesicle, endocervix, fallopian tube, and respiratory epithelium. HMGA2 expression was generally markedly higher in cancer than in corresponding normal tissues. HMGA2 staining was found in 2,695 (42.7%) of the 6,313 interpretable tumor samples, including 701 (11.1%) with weak, 769 (12.2%) with moderate, and 1,225 (19.4%) with strong positivity. A total of 93 of 115 tumor categories showed HMGA2 expression in at least one case, and 69 tumor categories included at least one case with strong HMGA2 staining. The frequency of HMGA2 positivity was particularly high in cancers of the ovary and the endometrium (52.6-92.6%), pancreatico-biliary cancers (48.1-75.5%), thyroidal neoplasms (53.4-95%), salivary gland neoplasms (66.7-98%), nonseminomatous testicular germ cell tumors (73.5-93.5%), colorectal adenocarcinoma (81.6%), papillary renal cell carcinoma (68.2%), and in squamous cell carcinomas (36-81.5%). Tumor entities with a particularly low expression of HMGA2 included prostatic adenocarcinomas (1.3-4%), non-invasive urothelial carcinomas (1.8-4.3%), hepatocellular carcinoma (3.2%), and non-Hodgkin’s lymphomas (0%) It is concluded, that HMGA2 is highly expressed in a very broad range of tumor entities. These findings emphasize a potential role of HMGA2 as a drug target and demonstrate utility for HMGA2 IHC for the distinction of neoplastic from non-neoplastic tissues in several organs. Citation Format: Katharina Möller, Florian Lutz, Florian Viehweger, Martina Kluth, Claudia Hube-Magg, Christian Bernreuther, Guido Sauter, Andreas H. Marx, Ronald Simon, Till Krech, Stefan Steurer, Christoph Fraune, Sarah Minner, Natalia Gorbokon, Maximilian Lennartz, Eike Burandt, Anne Menz. High mobility group protein 2 (HMGA2) is highly expressed in a broad range of human cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6450.