a general regulator of motor neuron survival, likely owing to reducing activation of the endoplasmic reticulum (ER) stress response. Moreover, inhibitors of the degradation process do not promote survival of SMN neurons below a defined basal level but shift the distribution of SMN, producing more neurons with levels that support survival. On the other hand, compounds that reduce ER stress don’t affect SMN levels at all but still promote motor neuron survival. Lee summarized problems that arise in high-throughput screening of hiPSC-derived cells as those arising due to issues of neuronal variability, immaturity, and non-cell-autonomous disease-relevant interactions.
