Statistical analyses of CECs were performed with GraphPad Prism 6 software. A chi-squared test was used to analyze differences in the distribution of foci incidence between the cells treated with the control and the (CAG)7 ASO. Odds ratio tests were performed to analyze whether the likelihood of finding 0, 1, 2, 3, or 4 or more foci after treatment was increased or decreased. An unpaired two-tailed t test was used to calculate the difference in mean number of MBNL1-positive foci per nucleus between control and (CAG)7 ASO treatments. A one-way analysis of variance (ANOVA) using Dunnett’s multiple comparisons test with a single pooled variance was used to analyze differences between mean amplicon expression in expansion-negative and expansion-positive CEC lines compared with controls. Paired two-tailed t tests were conducted to analyze the effect of (CAG)7 versus control ASO treatment on amplicon expression, for each respective transcript investigated. Data are represented as means ± 1 SD for bar graphs throughout the manuscript.