21. The major histocompatibility complex ( MHC ) is involved in the recognition of foreign antigens and cells. 22. Other factors that can have an impact on mate choice include Major Histocompatibility Complex ( MHC ). 23. Minor histocompatibility antigens are due to normal proteins that are in themselves polymorphic in a given population. 24. This gene is located in the class II region of the MHC ( major histocompatibility complex ). 25. The gene localizes to the major histocompatibility complex ( MHC ) class III region on chromosome 6. 26. This gene localizes to the major histocompatibility complex ( MHC ) class III region on chromosome 6. 27. The gene lies within the major histocompatibility complex ( MHC ) class I region on chromosome 6. 28. Bach's work on transplant compatibility helped in later experiments that identified the major histocompatibility complex. 29. HLA is the human form of the major histocompatibility complex ( MHC ) genes found in all vertebrates. 30. This is likely due to the presence on this chromosome of the major histocompatibility complex ( MHC ).