Stimulation of proliferation in EndoC-βH1 cells using the small molecule CHIR99021 (A) and the proteins SerpinA6, STC1, and APOH (B). A) Dose response of the GSK3-inhibitor CHIR99021 in concentrations between 0.625 μM and 10 μM with 2-fold increase of dose between each concentration as measured by 14C-Thymidine incorporation after 48 h treatment, n = 3; each experiment is based on 5–10 replicates for each condition. B) Effect of 100 nM SerpinA6, 10 nM STC1 and 100 nM APOH determined by 14C-Thymidine incorporation after 48 h treatment, n = 2–3. Data are shown as mean + SEM. P-values determined by unpaired One Way ANOVA and Student's t-test. The * symbol illustrates significant difference from non-treated control cells *∼p < 0.05; **∼p < 0.01.