CYCS and Parkinson disease: Analysis of the effects of PD-linked PINK1 mutations on cytochrome c release showed that the W437X mutation caused a significant increase in H2O2-induced cytochrome c release compared to cells expressing similar level of exogenous wild-type PINK1 (Figure 4B and 4C), in agreement with the observed effect of the W437X mutation on the cytoprotective function of PINK1 (Figure 4A).