PINK1 and Parkinson disease: However, many of the studies elucidating the mechanistic basis of Parkinson's have been performed in cultured cell lines, and despite much effort, the in vivo relevance of PINK1/Parkin‐mediated mitophagy was not well understood, particularly since mice that lack either PINK1 or Parkin exhibit no Parkinson's‐like disease phenotypes 140, 141, 142.