PID 203 and PID 319 (large filled squares) are plotted along with various AGN samples on the L_X–z plane: XMM-CDFS (filled squares, Comastri et al., in prep.; Ranalli et al. 2013), PG quasars (open circles, Piconcelli et al. 2005), SDSS quasars (crosses, Strateva et al. 2005), and CAIXA (filled circles, Bianchi et al. 2009). The L_X is the rest-frame 2−10 keV luminosity. The monochromatic 2 keV luminosities in Strateva et al. (2005) were converted to 2−10 keV luminosities assuming a power-law spectrum of Γ = 1.8.