TGFB1 and colorectal carcinoma: On the other hand, the markedly reduced peripheral concentration of IL-2, IL-15 and TGFβ in the CRC (Figure 1B,G,H) group could be explained by the advanced disease stage of the patients and the reported CRC-suppressive phenotype [8] of these cytokines or their ambiguous role (specifically for TGFβ); disease progression and chemotherapeutic treatment are logically associated with lower levels of signaling molecules with a potential anti-tumor role.