Molecular mass estimates compared to the dynamical mass either from the dust continuum emission (left panel; assuming standard conversion estimates; e.g., Venemans et al. 2016) or from the scaling between [C II] luminosity and molecular mass (right panel; Zanella et al. 2018). In the latter case, the [C II]-based molecular gas mass estimate is unphysically higher than the dynamical mass estimate, suggesting that the scaling relationship derived in Zanella et al. (2018) for main-sequence galaxies at z ∼ 2 does not apply to z ≳ 6 quasar host galaxies. We find that the gas mass estimates derived from the dust continuum are lower than the dynamical mass estimates, as expected, because the dynamical mass accounts for all mass components within the given radius, including the gas.