TCF12 and frontotemporal dementia: Regarding intervention, the community should consider the possibility that a correction in one cell type might cause problems in another, as the “wrong” isoform in one cell type could be the “correct” isoform in another—as seen, for instance, in an exon of TCF12, where neurons in FTD exhibit the low inclusion rate that is seen in both FTD and control astrocytes.