We observed a high correlation between CD8+ T cell fractions and the expression of CXCL9 chemokine (Fig. 3a) and chemokine receptor CXCR3 (Additional file 2: Figure S11b) and, for some cancer types, with CXCL10 expression (Additional file 2: Figure S11a). The gene discussed is CXCL9; the disease is cancer.