Moreover, Dannuli et al.,[38] demonstrated that the elimination of Tregs using recombinant IL-2 diphtheria toxin conjugate DAB389 IL-2, acting like a CD25-specific antibody, reduced the number of Tregs present in the peripheral blood of metastatic RCC patients without severe side-effects and abrogated Treg-mediated immunosuppressive activity in vivo. Here, IL2 is linked to renal cell carcinoma.