Reduction or absence of SICI, which is a biomarker of cortical interneuronal inhibitory GABAergic function, has been established as an early feature of ALS (Figures 2A,B), correlating with biomarkers of peripheral neurodegeneration and at times preceding the onset of LMN dysfunction in sporadic ALS cohorts [(31, 53), etc]. The gene discussed is LMNB1; the disease is amyotrophic lateral sclerosis.