We confirmed that upon TDP-43 knockdown, the MARK3 gene displayed increased expression of transcripts with a longer 3′ UTR in induced pluripotent stem cell–derived (iPSC-derived) neurons and an overall increase in transcript abundance in iPSC-derived neurons and in the frontal cortex of patients with frontotemporal lobar degeneration with TDP-43 pathology (FTLD-TDP). Here, MARK3 is linked to frontotemporal dementia.