Immunogenicity ligandome

Instead of trying to model the space of immunogenic epitope strings directly, instead let's model immunogenicity by only keeping track of which patterns *can't* be recognized by T-cells. These are epitopes which overlap with the set of "self" peptides used for negative selection in the thymus. 
It's the old immunogenicity predictor which tried to model immunogenicity as a direct property of amino acid strings. It's unclear how well it worked and was totally uninterpretable.