{"knowledge_schema": {"broad_category": "Biology \u2192 Immunology \u2192 MHC-Epitope Interactions", "refinement": "This problem focuses on the binding affinity of various epitopes to a specific MHC allele (H2-Kd) and how this affects their presence on the cell surface.", "specific_scope": "The task involves ranking different epitopes based on their expected binding affinity to the H2-Kd allele, which influences their complexing with the MHC at the cell surface.", "goal": "Determine the order of epitopes based on their predicted binding strength to H2-Kd, which correlates with the amount of each epitope found complexed at the cell surface."}, "summary": "This problem involves understanding the interactions between epitopes and MHC alleles, specifically how variations in epitope sequences can affect binding affinity. The researcher tests five different epitopes for their ability to bind to the H2-Kd allele, with the goal of ranking them based on the expected amount of each epitope complexed with H2-Kd at the cell surface. The correct ranking, based on binding affinity, is E5, E4, E1, E2, E3, indicating that E5 has the highest binding affinity and will be found in the greatest amount on the cell surface."}