<prompt> HLA complex in humans is located on?Long arm of chromosome 6Short arm of chromosome 6Short arm of chromosome 8Long arm of chromosome 8  <response>: Ans. b Short arm of chromosome 6. Ref Harrisons medicine 16th ed. 1930MAJOR HISTOCOMPATIBILITY COMPLEX MHC MHC is a gene cluster of various loci grouped together on a single locus. The MHC of humans, or the HLA complex, is located on the short arm of chromosome 6 approximately 32 CM from the centromere. The loci of the HLA complex may be divided into three classes: Class I, Class II, and Class III. The products of Class I and Class II genes play an important role in the communication between cells. These MHC molecules are surface proteins which present antigenic peptides to T lymphocytes. 