To assess whether deficiency of the Tcf7+22kb conferred cell-intrinsic advantages in memory potential, we reconstituted irradiated mice with a mixture of hematopoietic progenitor cells from congenically distinct WT and Tcf7Δ+22kb donors and monitored the ratio of WT to Tcf7Δ+22kb gp33-specific CD8+ T cells following LCMV-Arm infection (Figure 5C). The gene discussed is TCF7; the disease is infection.