More recent investigation also revealed that a transcriptional regulator of RNA polymerase II, the CDC73/PAF1 complex (PAF1C), and its components Leo1 and Paf1, are upregulated in transgenic (C4G2)49 Drosophila, (C4G2)149 mice, iPS cells from C9orf72 ALS patients and frontal cortex from C9orf72 ALS/FTD or C9orf72 FTD cases [91]. This evidence concerns the gene LEO1 and frontotemporal dementia.