CD8A and influenza: To analyse antigen specific responses in the absence of IKK2, we analysed the F5.Rag1−/− huCD2iCreIkk2flox strain (F5Ikk2ΔTCD2 hereon) of TCR transgenic mice whose CD8+ T cells are specific for NP peptide from influenza, but lack IKK2 expression [44, 45].