Example of PIT distribution (left) and redshift distribution (right) for a tomographic bin selected at 0.6 < z_p < 0.8. Top and bottom panels: assume photo-z errors that are underestimated (A = 0.7) and overestimated (A = 1.5), respectively. The PIT distribution used to correct the zPDF is shown with the solid black line. The inset shows an example of the de-biased zPDF for one galaxy (selected randomly). The resulting PIT distribution, after de-biasing, is shown in dashed red. The true N(z) is shown with the blue histogram in the right panels. The N(z) reconstructed using the initial and the de-biased zPDFs are shown with black solid lines and red dashed lines, respectively.