RB1 and cancer: Takahashi et al. (2020) reported the excited-state intramolecular proton transfer reaction was significantly induced and the intensity of the tautomer emission band of Fis (21) was enhanced when Fis (21) bound to the VEGF i-motif, which could be used for the diagnosis of cancers associated with VEGF. In addition, thioflavin T (61,Figure 9) can distinguish structural changes in RET and Rb i-motif sequences based on pH changes; thus, it can be used as a special probe for these two nucleotide sequences and may play a good supporting role in genetic diagnosis and treatment (Lee et al., 2015).