Initial gene activation was conserved in chemical reprogramming from different cell types. (A) Expression of Sall4, Gata6 and Sox17 at the early stage of chemical reprogramming from NSCs (day 0 (D0), day 4 (D4) and day 16 (D16), respectively) measured by quantitative real-time PCR (error bars, mean ± SD, n = 3). (B) Expression of Sall4, Gata6 and Sox17 genes at day 16 of the reprogramming by the chemical cocktail with different concentration of 616452 (error bars, mean ± SD, n = 3). (C) Expression of Sall4, Gata4 and Sox17 genes at the early stage of chemical reprogramming from IECs (day 0 (D0), day 4 (D4) and day 16 (D16), respectively) measured by quantitative real-time PCR (error bars, mean ± SD, n = 3). (D) Expression of Sall4, Gata4 and Sox17 genes at day 20 of the reprogramming by the chemical cocktail with different concentration of 616452 (error bars, mean ± SD, n = 3). (E) Expression of pluripotency genes Sall4, Lin28, Esrrb, Dppa2 and Oct4 during the chemical reprogramming from NSCs (day 0 (D0), day 4 (D4), day 12 (D12), day 16 (D16) and day 20 (D20)) measured by quantitative real-time PCR (error bars, mean ± SD, n = 3). (F) Schematic diagram illustrating the step-wise chemical reprogramming of different cell types.