(a) Hierarchical clustering based on global gene expression measured by microarray of a subset of T1D and ND SC-β cell lines sorted for INS and NKX6-1. Individual replicates shown. (b) The average relative fraction of T1D and ND SC-β cells immunostained for C-peptide (CP) and NKX6-1 treated 24 h with the indicated stressor normalized by untreated cells. n=3 T1D and 4 ND SC-β cells batches (7 batches total). (c) The average relative fraction of cells immunostained for C-peptide and PDX1, NKX6-1 or MAFA treated up to 48 h with interleukin (IL)-1β, tumour necrosis factor (TNF)-α and interferon (IFN)-γ n=3 T1D and 4 ND SC-β cells batches (7 batches total). (d) Box and whiskers plot comparing of the relative fraction of C-peptide+/NKX6-1+ cells for T1D-1 (n=6), T1D-2 (n=4), T1D-3 (n=3), ND-1 (n=4), ND-2 (n=6) and ND-3 (n=5) after 24 h treatment with IL-1β, TNF-α and IFN-γ (28 batches total). The cross indicates the mean, the line the median and each circle is one biological replicate. (e) Representative images of immunostained cells not treated, treated with IL-1β, TNF-α and IFN-γ, or treated with IL-1β, TNF-α, IFN-γ and Alk5i for 24 h. Scale bar, 20 μm. (f) Average relative fraction of C-peptide+/NKX6-1+ cells treated with IL-1β, TNF-α and IFN-γ either without (left) or with (right) Alk5i for 24 h. n=10 T1D and 7 ND SC-β cells batches (17 batches total). Quantification of immunostained cells in this figure was performed with Cellomics ArrayScanVTI. *P<0.05 (two-sided paired t-test). Experiments were performed on and samples taken from cells after 10–17 days in Stage 6. Arg, arginine; Bor, bortezomib; Glu, glucose; IFN, interferon-γ; IL, interleukin-1β; Tha, Thapsagargin; TNF, tumour necrosis factor-α; Tol, tolbutamide. Data shown as mean±s.e.m.