https://phys.org/news/2018-08-newly-class-molecules-boost-cancer.html

Dubbed "retained intron neoantigens," these potential immune triggers stem from short segments of noncoding DNA within genes—called introns—that are typically spliced out when genes are translated into proteins. In cancer, however, introns often get translated into a gene's final protein product.  

The team developed and applied an algorithm that could identify these retained introns from 48 melanoma patients who had been treated with a form of cancer immunotherapy called a checkpoint inhibitor. By including retained introns in their analysis, the team roughly doubled the number of neoantigens they could identify. These new peptides, they found, bind to a molecule called MHC class I—the first step toward being recognized by the immune system.