Mass spectrometry-based de novo sequencing reveals non-canonical neoantigens with antitumor efficacy in hepatocellular carcinoma

This study provides robust experimental validation that mass spectrometry-based de novo sequencing effectively identifies novel, highly immunogenic non-canonical neoantigens in hepatocellular carcinoma, overcoming a key limitation of prior predictive methods and opening avenues for exploring this understudied neoantigen class in other cancers. The findings are critical for cancer immunologists and oncologists developing next-generation immunotherapies, demonstrating a viable discovery-to-validation pipeline for novel therapeutic targets. The validated neoantigens and successful peptide vaccine strategy offer a direct pathway towards developing personalized hepatocellular carcinoma immunotherapies, enabling clinicians to adopt similar integrated approaches for patient-specific neoantigen discovery; however, clinical translation beyond this preclinical murine model requires confirmation in human settings due to potential differences in HLA presentation and the tumor microenvironment.