Our observation that a protein including the LeuR of RGNEF is part of a protein complex containing TDP-43, and also co-localizes in vivo with TDP-43, not only confirmed our previous observation about the interaction between TDP-43 and full length RGNEF11, but also indicated that the LeuR domain may be critical for the formation of the RGNEF-TDP-43-containing aggregates observed in motor neurons of ALS patients11,12. This evidence concerns the gene ARHGEF28 and amyotrophic lateral sclerosis.