TGFB1 and cancer: Considering Foxp3+ expression in cancer cells as a continuous variable, regression analysis showed that Foxp3+ cancer cell expression had a weak but significant direct correlation with the expression of the immunosuppressive cytokines IL-10 (R2 = 0.23, p<0.001, n = 65; r = 0.48) and TGF-β (R2 = 0.33, p<0.001, n = 65; r = 0.57) (Figure5A and B).