Identification of tumor-associated antigens (TAAs) recognized by T cells has enabled clinical peptide vaccination trials targeting TAAs to be performed for patients with carcinoma or sarcoma. Although peptide vaccination could elicit specific immunological responses, clinical objective responses were not frequently observed, especially in end-stage patients with large tumor burdens who were receiving high-dose chemotherapy. The key points for developing effective peptide vaccination therapy are (i) targeting cancer stem-like cell antigens that are expressed in cancer cells but not in normal cells and regulating tumorigenesis and (ii) manip- ulating memory T stem cells that have the capacity of long-living and resistance to chemo- therapeutic drugs. The combination of a peptide vaccination and immune checkpoint inhibi- tors might also be attractive.