On the basis of the evidence that RET promoter contains a typical G4 forming motif (Figure 3A) and on the observed NDI-mediated decrease of RET levels in cancer cells (Figure 1 and Supplementary Figure S1), we investigated by biophysical assays whether the NDI derivative was able to favor the formation and/or the stabilization of G4 structures within the RET promoter. The gene discussed is RET; the disease is cancer.