PINK1 and Parkinson disease: A systematic study, in which multiple laboratories conducted analyses in parallel, revealed that neurons differentiated from familial PD patient [PTEN-induced putative kinase 1 (PINK1) Q456X homozygote, LRRK2 G2019S homozygote, LRRK2 R1441C heterozygote]-derived iPSCs exhibited increased vulnerability to various cytotoxins, such as the antibiotic valinomycin, the H+-ATPase inhibitor concanamycin A and hydrogen hyperoxide [35].