Zou Q, Zhang L, Cheng Z, et al. - In view of the emergence of insulinoma-associated protein 1 (INSM1) as a promising diagnostic marker for high-grade neuroendocrine carcinomas (HGNECs), researchers here examined if the sensitivity of INSM1 is more than conventional markers chromogranin, synaptophysin, and CD56. Immunohistochemical expression of INSM1 was determined in 75 gynecologic HGNECs using full tissue sections (30 small-cell carcinomas [SmCCs], 34 large-cell neuroendocrine carcinomas [LCNECs], and 11 mixed SmCC and LCNEC), with specificity analysis performed in 422 gynecologic non-neuroendocrine tumors (410 in tissue microarrays and 12 full sections) and comparison was done with conventional neuroendocrine markers for their sensitivity and specificity. Findings from the literature review suggest consistently higher or similar sensitivity of INSM1 (the same antibody clone A8 used for all reported studies) to chromogranin (for all 3 chromogranin antibody clones LK2H10, DAK-A3, DAKO polyclonal). However, the relative sensitivity of INSM1 to synaptophysin or CD56 for HGNECs is greatly dependent on the antibody clones employed for synaptophysin (clones MRQ-40 and SNP88 showing higher sensitivity than clones 27G12 and DAK-SYNAP) or CD56 (clones CD564, MRQ-42, and MRQ-54 showing higher sensitivity than clones 123C3D5, 1B6, and Leu243).