Insulin expression induced by transfection of the candidate factors in HEK-293 cells. Results are displayed in insulin relative units (x10−5) as mRNA levels were normalized with both GAPDH and AIRE. Cells were transfected with one of the three reporters (E1, 814 or noVNTR), in combination with human Jun, Ewsr1 or Zbtb7a, with or without AIRE. As controls, reporters were transfected alone, with human Pdx-1, with human AIRE or with both Pdx-1 and AIRE. Experiments were carried out in triplicates. Error bars represent standard deviation. Statistics determined by a two-way ANOVA. Reporters: E1 (class III), white; 814 (class I), grey and noVNTR, dark grey.