For this, we used the same human SOD1D90A-mutant ALS patient-specific iPSC line to derive spinal astrocytes15 (onwards ALS astrocytes), in which the increased PHLDA3 protein levels and predominant cytoplasmic protein distribution were originally observed by mass spectrometry and immunolabelling, respectively.7 First, we confirmed the PHLDA3 distribution pattern required for cytoplasmic signalling and the cellular protein abundance. Here, PHLDA3 is linked to amyotrophic lateral sclerosis.