This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
T4 cells recognizes antigen in association with all of the following EXCEPT: September 2004 
Select and explain. 
A. Major histocompatibility factor/ MHA-I, B. MHA-II, C. HLA-DR, D. HLA-DZ
A: Major histocompatibility factor/ MHA-I
Answer: A: Major histocompatibility factor/ MHA-I 
Explanation: Ans. A i.e. Major Histocompatility factor/ MHA-I HLA complex of genes are: HLA-A, B, C (Class I) HLA-D, DR, DQ and DP (class II) CD8 (previously known as T8) molecule is present on suppressor and cytotoxic cells. They recognize antigen by MHC class-I molecule.