To determine whether there was a direct effect of TSLP on virus-specific CD8+ T cells during influenza infection, we co-transferred equal numbers of congenically-labeled naïve WT and Crlf2-/- P14 T cells into WT recipient mice, infected them intranasally with PR8-33, and assessed TSLPR expression as well as WT and Crlf2-/- T-cell numbers and function, both at the peak of the response (day 8) and after the formation of memory cells (>day 30 p.i.)(see schematic in Figure 1B, upper panel and transferred cells lower panel). This evidence concerns the gene CRLF2 and influenza.