Immune modulation of intratumoural CD8 + T cells was also altered in mouse colon cancer models when colonised with either Bifidobacterium pseudolongum, lactobacillus or Olsenella species, compared to germ-free controls; an improvement in the efficacy of CTLA4 targeted immunotherapy was seen, with a significant decrease in both tumour size and weight compared to germ-free controls [88]. The gene discussed is CD8A; the disease is neoplasm.