XIAP and Parkinson disease: This effect was also applied to neuronal cells, i.e., K-560 (1a) exerted protective effects against 1-methyl-4-phenylpyridinium ion/1-methyl-4-phenyl-1, 2, 5, 6-tetrahydropyridine (MPP+/MPTP)-induced neuronal death through the sustained expression of X-linked inhibitor of apoptosis protein (XIAP) in vitro and in vivo in a Parkinson’s disease model23–25.