875
Dilutions of H - 2b or H - 2d NP peptides indicated that 3 - 4 logs less H - 2b NP peptide was required to sensitize syngeneic target cells for CTL - specific lysis , suggesting that the differing affinities of H - 2b and H - 2d major histocompatibility complex molecules for their peptides likely account for the total removal of NP CTL in the H - 2b mice but only partial removal in H - 2d mice made to express thymic NP .
 GENE: H - 2b or H - 2d NP peptides; GENE: H - 2b NP peptide; GENE: major histocompatibility complex molecules
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: GENE 
Text: {0} 
Answer:
 GENE: H - 2b or H - 2d NP peptides; GENE: H - 2b NP peptide; GENE: major histocompatibility complex molecules