Cluster of differentiation 30 (CD30) is a transmembrane cytokine receptor expressed by activated T and B cells. CD30, TNF-receptor superfamily member, is a receptor for TNFSF8/CD30L. TRAF2 and TRAF5 can interact with this receptor and mediate the signal transduction that leads to the activation of NF-kappaB. This receptor is a positive regulator of apoptosis, and it also has been shown to limit the proliferative potential of autoreactive CD8 effector T cells and protect the body against autoimmunity. 

It is present on Reed-Sternberg cells in Hodgkin's lymphoma, most anaplastic large cell lymphomas, embryonal carcinomas, and primary cutaneous CD30 positive T-cell lymphoproliferative disorders. B-cell lymphomas are sometimes stained by Anti-CD30. Lymphomas exhibit Golgi zone accentuation when stained with Anti-CD30, while embryonal carcinomas produce membranous stains. It has been useful in identifying Hodgkin's lymphoma, anaplastic large cell lymphomas (ALCL) and primary cutaneous CD30+ T-cell lymphoproliferative disorders. In non-lymphoid malignancies, CD30 reactivity has been reported in embryonal carcinomas (ECs), seminomas, and hepatocellular carcinomas.