(A) mRNA expression levels of Cacna1c and Cacna2d1 that encode CaV1.2 and Ca2d1, respectively (control siRNA, Control; Tardbp siRNA, T1 or T2) (Cacna1c, n = 6; Cacna2d1, n = 12 each, 1-way ANOVA). (B) Immunoblotting of MIN6 cells transfected with control, T1, or T2 (n = 6 each, one-way ANOVA). (C) Mock or CaV1.2 plasmid was cotransfected into MIN6 cells with control or T1 siRNA (n = 4 each, 1-way ANOVA). (D) The insulin assay with low and high glucose (n = 6 each, 1-way ANOVA). (E) In situ hybridization of the islets of disease control and ALS subjects with a human CACNA1C mRNA antisense probe. Scale bars: 20 μm. (F) Quantitative analysis of in situ hybridization of human CACNA1C, CACNA1D, and CACNA1A (n = 4 patients each, unpaired t test). Values are mean ± SEM. *P < 0.05; **P < 0.01; ***P < 0.005; ****P < 0.001.