It is part of the MHC class II.
CD78 is expressed on all stages of B cell development from pre-B cell through plasma cells. Its expression is strongest on activated B cells.
With flow cytometry, it can be used to detect B cells during many stages of their development. It is one of relatively few markers usefully expressed on plasma cells, and when combined with detection of markers such as CD22, can be used to determine the relative proportion of plasma cells.
- Slack JL, Armitage RJ, Ziegler SF, Dower SK, Gruss HJ (July 1995). "Molecular characterization of the pan-B cell antigen CDw78 as a MHC class II molecule by direct expression cloning of the transcription factor CIITA". International immunology. 7 (7): 1087–92. doi:10.1093/intimm/7.7.1087. PMID 8527406.
- "CD78 antibody (60-3G2) (ab24151) datasheet". Abcam. Retrieved 2008-10-28.
- Bona, Constantin; Francisco A. Bonilla (1996). "5". Textbook of Immunology. Martin Soohoo (2 ed.). CRC Press. p. 102. ISBN 978-3-7186-0596-5.