Equal number of congenically labeled WT (CD45.2+, Thy1.1+) and Ezh2−/− (CD45.2+, Thy1.2+) Pmel-1 cells were co-injected into non-irradiated B6/SJL mice (CD45.1+, Thy1.2+), followed by infection with vaccinia virus encoding gp100 (VVA-gp100). The gene discussed is PMEL; the disease is infection.