Rest-frame LF at 1.4 GHz for all galaxies simulated with SPRITZ (solid black tick line) with high-redshift extrapolation k_Φ = −1 (Eq. (2)), taking into account only the luminosity originated from the star formation activity. The grey areas indicate the uncertainties due to the high-z extrapolation, the different torus models included, and the 1σ errors of the GSMF, IR, and K-band LFs used to generate simulated galaxies. The LF for each different sub-population is also shown (see Fig. 17). The observed 1.4 GHz LFs, limited to the star-formation activity, by Novak et al. (2017, red squares), Bonato et al. (2021, blue circles), Smolčić et al. (2009, green trangles), and Upjohn et al. (2019, orange stars) are represented.