The term NUT antibody refers to an antibody used to detect a protein called NUT (Nuclear Protein in Testis). The NUT protein is involved in various cellular processes, and its abnormal expression has been associated with certain cancers, particularly NUT carcinoma. NUT carcinoma is a rare and aggressive type of cancer that primarily affects the thoracic and head and neck regions. It is characterized by the presence of a NUT fusion gene, typically resulting from a chromosomal translocation. NUT antibody staining is nuclear with > 90% of cells positive, and the reported sensitivity is 87% and the specificity is 100%. NUT is variably expressed among germ cell tumors, including dysgerminoma (60-90%), immature teratoma (75%), and spermatocytic seminoma (100%).