While it is feasible to argue that IFN-γ produced by CD8+ T cells within the tumour acts in a positive feedback loop to induce further CXCL10 expression from SCC cells, leading to further CD8+ T cell infiltration, this loop does not explain the initiating, hematopoietic, source of IFN-γ within the tumour microenvironment that led to CXCL10 induction in the first place. This evidence concerns the gene CD8A and neoplasm.