Survival curves for patients with or without increased CTL responses after PPV. a-f) CTL boosting was suggested to be a potential prognostic factor for OS but not for PFS in mrTNBC patients, whereas there was no significant difference between CTL boosting and these prognoses in luminal/HER2-negative and HER2-positive patients. a, b) mrTNBC: PFS and OS, P = 0.345 and P = 0.053, respectively. c, d) luminal/HER2-negative type: PFS and OS, P = 0.272 and P = 0.740, respectively. e, f) HER2-positive type: PFS and OS, P = 0.714 and P = 0.758, respectively. CTL, cytotoxic T lymphocytes; HER2, human epidermal growth factor receptor 2; mrTNBC, metastatic recurrent triple negative breast cancer; OS, overall survival; PFS, progression-free survival; PPV, personalized peptide vaccination.