Upon infection, both the percentage and the total number of CD8+ T cells (Figures 6A,B), as well as PbA-specific H2-Db SQLLNAKYL pentamer+ CD44+ CD8+ T cells (Figure 6C), were significantly increased in the brains of WT mice at day 7 p.i. Numbers of PbA GAP-50-specific CD8+ T cells producing IFN-γ, TNF, and granzyme B were reduced in the brains of Cyld−/− mice (Figure 6D). The gene discussed is CD44; the disease is infection.