The obtained results indicated that the expression level of TMPRSS2 has a considerable association with tumour purity, neutrophils, CD8+ T cell and dendritic cell in BRCA; CD4+ T cell, B cell, DCs and neutrophils in COAD; B cell, macrophages, CD4+ T cell and dendritic cell in LUAD; and tumour purity and dendritic cell in OV respectively (Figure 8). The gene discussed is CD8A; the disease is neoplasm.