CD8A and cancer: Similarly, in Gatti-Mays et al.’s Phase I clinical trial, adenovirus 5 vector vaccines ETBX-011, ETBX-051, and ETBX-061, targeting CEA, MUC1, and brachyury, were administered safely to advanced cancer patients, eliciting CD4+ or CD8+ T cell responses to at least one vaccine-encoded antigen in all patients, with 83% demonstrating significant specificity to MUC1 (175).