TEM analysis of treated and untreated EndoC-βH3. Non-treated and treated EndoC-βH3 cells were analyzed after Epon embedding and ultrathin sectioning. (A) Non-treated EndoC-βH3, inset: detail of insulin SGs, (B) TAM-treated EndoC-βH3, inset: detail of insulin SGs. Scale bar: 2 μm. Labeling key: Nuc, nucleus; Mito, mitochondria; SG, secretory granules; arrowheads, degradative compartments.