– Gallocyanine is a small molecule blue dye used to stain nuclei. It is known to inhibit Dickkopf-1 (Dkk1), an antagonist of the Wnt pathway. Gallocyanine can disrupt the interaction of Dkk1 with its receptor LRP5/6 (IC50 = 3 μM), thereby activating Wnt/β-catenin signaling. Modulation of the Dkk1-LRP5/6 interaction via gallocyanine has been shown to inhibit prostaglandin J2-induced tau phosphorylation at serine396 in primary cortical neurons in vitro.