Human recombinant OXR1 protein (OriGene TP760961) was incubated with biotin-labeled piperlongumine (PL), a novel senolytic agent, in the absence or presence of a fivefold excess of unlabeled PL followed by immunoblotting with antibodies against biotin to detect OXR1 bound to the biotin-labeled PL probe. An immunoblot of OXR1 from each reaction was included as input control. Figure cited from Aging Cell, PMID: 29766639