In addition, an mRNA vaccine encoding neoantigens induced specific T-cell immune responses in patients with gastrointestinal cancer.197 The mRNA-based vaccine mRNA 4650 was clinically evaluated for the treatment of various digestive system cancers, including gastrointestinal cancer and liver cancer.198,199 Patients with gastrointestinal cancer treated with an intramuscular administration of mRNA 4650 developed CD4+ and CD8+ T-cell responses against tumor neoantigens. This evidence concerns the gene CD8A and neoplasm.