conducted a phase I clinical trial evaluating the tumor vaccine Ad5-GUCY2C-PADRE(adenovirus vector vaccine) in patients with early-stage colorectal cancer, none of which had an adverse event greater than grade I. GUSY2C antibody responses were seen in 10% of patients, while GUSY2C-specific CD8 cytotoxic T cell responses were seen in 40% of patients (29). Here, CD8A is linked to colorectal cancer.