Sivan et al. have reported that a cocktail of lyophilized Bifidobacteria species, when administered in mice bearing B16.F10 melanoma, resulted in the development and accumulation of highly effective tumor-specific CD8+ cells, which in combination with anti-programmed cell-death ligand 1 (PD-L1) treatment, nearly abolished tumor overgrowth [28]. The gene discussed is CD8A; the disease is neoplasm.