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antilymphocyte serum

[ăn′tē-lĭm′fə-sīt′, ăn′tī-]
n.
  1. The globulin fraction of serum from a horse or another animal, usually used in conjunction with other immunosuppressive agents to suppress rejection of grafts or organ transplants.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.