L_[CII]–SFR relation for galaxies that follow the selection of the simulated galaxy sample by Olsen et al. (2017) at z ~ 6. Our 575 selected galaxies are shown with coloured points (with colour scale reflecting the gas metallicity). Olsen et al. (2017) sample is shown with grey points. The black and the grey solid lines show the mean trend of our whole galaxy sample (Eq. (10)) and of Olsen et al. (2017) sample (their Eq. (6)), respectively. The black dashed line marks the mean trend of our galaxy selection.