Comparison between the stellar mass and the star formation rate estimates for the eastern (red) and western (blue) companion galaxies in PJ308–21. We also show the location of the quasar host galaxy, assuming that the stellar mass takes accounts for 50% of the dynamical mass, and that the star formation rate is dominated by the emission traced by the dust. For comparison, the best fit main sequence of star forming galaxies at z = 6 based on the FLARES-JWST simulations and the SHARK-JWST simulations are shown as dashed lines (D’Silva et al. 2023), while the sample of photometrically selected 5.5 < z < 7.0 galaxies from the UNCOVER survey (Wang et al. 2024) are shown as gray points. Both companion galaxies in PJ308–21 appear to lie along the expected main sequence at these redshifts, at the high–mass end of the galaxy population observed at these redshifts.