Updated FTP location. HLA Class I immunopeptides were affinity purified by W6/32 antibody and analyzed by Orbitrap Fusion Lumos with FAIMS. Customized database which includes somatic mutations of HCT116 obtained from COSMIC database was used for database search. Identification results were filtered at 1% FDR thresholds by searching against a randomized decoy database using Proteome Discoverer 2.4 (Sequest HT).