GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE305nnn/GSE305345/primaryOK200TranscriptomicsHomo sapiensExpression profiling by high throughput sequencinghttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE305345GEOGSEfalseLINE-1 ORF1p is a Shared and Immunogenic Antigen in CancerIn this study, we identify and characterize LINE-1 ORF1p as a shared and immunogenic cancer antigen. LINE-1 elements are normally repressed genomic sequences that can be reactivated in cancer. We demonstrate that ORF1p, a protein encoded by LINE-1, is selectively expressed in tumors and its peptides are presented on MHC class I molecules across diverse tumor types. Using public and newly generated immunopeptidomics datasets, we detect ORF1p-derived peptides in a tumor-specific manner. Functional assays confirm that these peptides can elicit IFN-γ responses from CD4+ and CD8+ T cells in vitro. These findings highlight ORF1p as a promising candidate for a broadly applicable cancer vaccine.2026/08/14GSE305345GSM9169059GSM9169056GSM9169066GSM9169055GSM9169058GSM9169057GSM9169052GSM9169063GSM9169062GSM9169065GSM9169054GSM9169064GSM9169053GSM9169061GSM916906016791305345Homo sapiens