Like Rpn10 RAZUL, there are several therapeutically-relevant proteins that are intrinsically disordered, contain disordered domains, and/or exhibit extensive folding upon binding to a partner.69–72 An attractive cancer target that contains disordered regions is tumor suppressor p53,43,44 and we expect that environmentally sensitive fluorophores could be applied to discover p53-binding compounds and/or compounds that disrupt the E6-driven interaction of E6AP with p53. The gene discussed is PSMD4; the disease is cancer.