Importantly, restoring GAP43 expression after TDP‐43 depletion rescued axonal growth cone formation in M17 cells, and reversed axonal regeneration defects in induced pluripotent stem cell (iPSC)‐derived motor neurons, suggesting that GAP43 restoration could be a potential therapeutic strategy for TDP‐43 proteinopathies, particularly ALS and AD. Here, GAP43 is linked to proteostasis deficiencies.