System and method for identification of a synthetic classifer

A method for identifying a synthetic classifier, the method comprising:

• contacting at least a first sample and a second sample with a first plurality of peptides, the first sample derived from a first group of a cohort, the second sample derived from a second group of the cohort, the first group being different from the second group, and the first plurality of peptides including:
• i) a first subset of peptides defining at least one naturally occurring amino acid sequence, and
• ii) a second subset of peptides defining a plurality of variant peptides of the first subset of peptides, the plurality of variant peptides including for each one of the first subset of peptides, a variant peptide having at least one of a substitution, a deletion, an insertion, an extension, and a modification relative to a corresponding one of the first subset of peptides;
• selecting at least one of the plurality of variant peptides from the second subset of peptides;
• and
• defining a synthetic classifier including the at least one of the plurality of variant peptides, the synthetic classifier distinguishing between a sample derived from the first group and a sample derived from the second group.