This indicates that amino acid diversity in the initial peptide batch is critical. The multi-alanine scanning's limited chemical diversity hinders the ability of the GPR model to adequately interpolate to other amino acids, thus failing to suggest new peptide sequences with improved pIC50s. That other sequence-based strategies performed comparably, including scrambled scanning, suggests a possible limitation of the MHC class I receptor system used here: its permittivity may not allow clear differentiation between strategies' effectiveness. In more restricted systems, where the amino acid natures at specific positions is crucial for binding, mutations to structurally distinct amino acids (e.g. Asp/Glu to Arg/Lys) could disrupt interactions. In such cases, the homolog scanning strategy (e.g. Asp replaced by Glu or Gln/Asn), introducing the least possible structural disruption upon side chain substitutions, might be proven more effective compared to the other sequence-based strategies.