PRF1 and neoplasm: Furthermore, tumor cells pre-incubated with Ara-C stimulated more perforin (MFI: CD8+: 28.24 ± 1.18, CD4+: 16.77 ± 1.35) and granzyme B (MFI: CD8+: 35.47 ± 1.20, CD4+: 22.30 ± 0.40) than tumor cells alone.