In contrast, CD8+ T cell responses against F4 peptide mostly comprised single cytokine positive cells, TNF?? or IFN??, a low number of dual cytokine positive cells, TNF?? and IFN?? or TNF?? and IL-2, and a low number of triple cytokine positive cells, TNF??, IL-2 and IFN?? (Figure 4C and D).