This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
MHC class - III genes encode 
Select and explain. 
A. Complement component C3, B. Tumor necrosis factor, C. Interleukin-2, D. Beta-2 microglobulin
B: Tumor necrosis factor
Answer: B: Tumor necrosis factor 
Explanation: Structure - Major histocompatibility complex, (HLA) complex MHC class III genes encode Complement components C2 and C4 Properdin factor B of alternate pathway TNF - alpha and beta Heat shock proteins Also known as "complement region"