C9orf72 and Atrophy: Our analyses replicate and build on these findings by demonstrating that mediodorsal (i.e., R MDl nucleus) and pulvinar (i.e., R anterior pulvinar nucleus) atrophy remain significantly associated with C9orf72 HRE status even after correcting for thalamic atrophy, a unique and important finding given the pronounced global thalamic atrophy observed in HRE carriers (Bocchetta et al., 2020; Spinelli et al., 2021).