Since Treg depletion was observed in tumor tissue but not in the spleen of mice, and only occurred in the presence of vaccination-activated gp100-specific CD8+ Teff (Supplementary Fig. 4d), we hypothesized that intratumoral Treg depletion is mediated by CD8+ Teff responding to cognate tumor antigen highly expressed in the tumor tissue. Here, PMEL is linked to neoplasm.