Luminosity function at 2–10 keV for all AGN simulated with SPRITZ (solid black line) with high-redshift extrapolation k_Φ = −1 (Eq. (2)) and for the sub-sample of AGN with log₁₀(N_H/cm⁻²) < 23 (dotted black line). The grey area shows the uncertainties due to the conversion from the L_12 μm to L_{2 − 10 keV}, the use of different torus models, and the 1σ errors of the IR LFs used to derive the simulated galaxies hosting an AGN. The LF for each different sub-population is also shown (see Fig. 17). The observed X-ray LFs by Wolf et al. (2021, purple star), Miyaji et al. (2015, cyan squares), Aird et al. (2010, red circles), Aird et al. (2015, green and orange triangles), and Vito et al. (2018, yellow diamonds) are reported.