MAPT and Alzheimer disease: Some years ago, we developed one of this class of multitarget anti-AD conjugate hybrids, designed by the combination of rhein 1 (Figure 1), a hydroxyanthraquinone scaffold with putative tau anti-aggregating activity [30,31], and the potent AChE inhibitor huprine Y 2 [32,33], or other modified huprine derivatives [34], connected by oligomethylene chains of different lengths.