Importantly, T cells targeting the patient's ‘private antigens’ i.e. tumor-associated mutations, including tumor ‘driver’ mutations such as V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genetic aberrations, are associated with tumor regression and long-term survival in patients with gastrointestinal tumors [4]. This evidence concerns the gene KRAS and neoplasm.