Anderson WJ, Maclean FM, Acosta AM, et al. - Researchers investigated the diagnostic utility of SSX_CT (a novel SSX antibody directed against the C‐terminus of SSX1, SSX2 and SSX4) immunohistochemistry in spermatocytic tumour (ST; a rare testicular germ cell neoplasm) and other tumors in the differential diagnosis with ST. This analysis included 15 STs, 38 seminomas, 13 embryonal carcinomas, 12 yolk sac tumours, 6 choriocarcinomas, 4 teratomas, 7 Sertoli cell tumors, and 6 lymphomas. SSX_CT, OCT3/4 and C‐KIT immunohistochemistry was conducted on these. Findings demonstrate usefulness as well as high sensitivity of SSX_CT as a biomarker that supports the diagnosis of ST. In 93% of STs (vs 6% of seminomas), diffuse expression was evident which is also highly specific for ST. Nevertheless, SSX_CT is best employed together with OCT3/4 when ST is in the differential diagnosis.