PRF1 and melanoma: The percentages of granzyme B-, perforin-, IFN-γ-positive CD8+ T cells in melanoma were also significantly increased to 53.1%, 49.5% and 34.9% of CD8+ T cells by NPTyr-C9AP treatment when compared to anti-PD-L1 group (Fig. 6g–i, Supplementary Fig. 24b–d).