CTLA4 and neoplasm: Within the cohort of patients in our study, intermetastatic differences in the individual tumor growth kinetics were particularly evident in patients undergoing anti-PD-1 monotherapy, as compared with patients receiving combined CTLA-4 and PD-1 treatment, where response was almost immediate at the 3-week MRI (figure 2A), which may represent the fact that monotherapy takes longer to mount antitumor effects compared with combination therapy.