<prompt> True about MHC -Present on chromosome 4Class II compromises A, B, C lociClass III has complementClass I is involved in mixed leucocyte reaction  <response>: MHC class III genes encode several components of the complement system i.e. C2, C4a, C4b, Bf, they are responsible for the levels of components of compliment system. Reff: Ananthanarayan Panikers textbook of microbiology 9th edition pg: 140 