Meaning of histocompatibility antigen

histocompatibil'ity an"tigen

Pronunciation: [key]
— Immunol. Immunol.
  1. any antigen on the surface of tissue or blood cells that provokes the immune response and subsequent rejection when transplanted to an individual of a different antigenic type, thus determining whether the tissues or organs of a donor and recipient are histocompatible.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.