In addition, it has been elucidated that an imperative ubiquitin E3 ligase, namely tumor necrosis factor receptor-associated factor 6 (TRAF6), is over expressed in the brains of individuals experiencing PD, and TRAF6 facilitates the trio, i.e., Lys6-, Lys27-, and Lys29-associated ubiquitination of α-synuclein and DJ-1, and in turn might precipitate the insoluble and polyubiquitinated mutant DJ-1 protein clumping. This evidence concerns the gene PRKN and Parkinson disease.