Carcinoembryonic antigen-related cell adhesion molecule 8 (CEACAM8) also known as CD66b (Cluster of Differentiation 66b), is a member of the carcinoembryonic antigen (CEA) gene family. Its main function is cell adhesion, cell migration, and pathogen binding.

CEACAM8 is expressed exclusively on granulocytes and used as granulocyte marker.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.