Since NRB-AF12 and ER-Tr showed the same cellular labeling pattern, we hypothesized a common target for these compounds. ER-Tr probes are conjugates of glibenclamide bearing different fluorophores, BODIPY FL (ER-Tr green) and BODIPY TR (ER-Tr red). Glibenclamide is an antidiabetic drug belonging to the class of sulfonylureas that binds the sulfonylurea receptor (SUR) subunits of ATP-sensitive potassium channels (Proks et al., 2002). Accordingly, we therefore explored the likelihood of whether NRB could also target these SURs by analyzing the co-localization between NRB-AF12 and the 2 major subunits SUR2A and SUR2B. We focused our attention on these SUR isoforms because of their intracellular distribution (Bao et al., 2011) and the role of the plasmalemmal SUR2B in the regulation of vascular contraction (Morrissey et al., 2005; Teramoto, 2006; Jackson, 2008; Tinker et al., 2014). Our results indicate that in LX2 cells NRB-AF12 co-localized with both SUR2A and SUR2B, with a greater correlation for the latter (Pearson's coefficient: 0.28 ± 0.02 and 0.36 ± 0.01, respectively for SUR2A and SUR2B; n ≥ 10) (Figures 8A,C,E); comparable results were also obtained with ER-Tr (Pearson's coefficient: 0.22 ± 0.04 and 0.32 ± 0.02, respectively for SUR2A and SUR2B; n ≥ 10) (Figure 8B,D,F). It is worth noting that the cellular distribution of NRB-AF12 and ER-Tr fluorescence was larger than that observed with SUR2, suggesting non-SUR2 additional targets for both dyes.