INSM1

Insulinoma associated protein 1 (INSM1) is a zinc finger transcription factor that is involved in embryonic development of the nervous system and neuroendocrine organs. In clinical practice, INSM1 is a highly specific and sensitive diagnostic biomarker for neuroendocrine neoplasm (NEN), including gastro-entero-pancreatic NEN, small cell lung cancer (SCLC), medullary thyroid carcinoma (MTC), etc. For example, INSM1 is positive in pancreatic neuroendocrine tumors but often negative in solid pseudopapillary tumors, acinar cell carcinoma, and ductal adenocarcinoma. Moreover, the high expression of INSM1 in SCLC can activate P13K/AKT/GSK3β pathway to promote tumor growth, making it become an independent risk factor for poor prognosis. Meanwhile, some breast cancer can express INSM1, speculated that it exhibits neuroendocrine differentiation, and INSM1 may promote cancer cell proliferation by positively regulating MYC. In addition, INSM1 can be expressed in some mesenchymal tumors such as rhabdomyosarcoma, Ewing's sarcoma, chondrosarcoma, and solitary fibroadenoma.