Trop-2 expression has also been described in some rare and aggressive malignancies, such as salivary duct carcinomas [19], anaplastic thyroid carcinomas [20], uterine/ovarian carcinosarcomas [21,22], and neuroendocrine carcinoma (NEC) of the prostate [23]. Here, TACSTD2 is linked to neuroendocrine carcinoma.