Earlier studies have suggested a possible positive correlation between the number of TILs and favourable prognosis [41,42]; however, it is important to consider the cell composition of the T-cell infiltrate; for example, in one study, the number of CD4+ T cells was shown to positively correlate with the tumour grade, while the level of CD8+ T cells was inversely correlated [39,40]. This evidence concerns the gene CD8A and neoplasm.