ISM scaling relations for the REBELS galaxies compared to the literature. Left: molecular gas-depletion timescale (t_dep) as a function of offset to the MS (∆_MS). Right: ratio of molecular gas to stellar mass (μ_mol) as a function of the offset to the MS (∆_MS). In both panels, filled orange circles show the REBELS galaxies z = 6–8 with molecular gas masses derived from [CII] measurements. The green triangles show [C II] measurements in ALPINE galaxies at z = 4–6 (Béthermin et al. 2020). The gray squares and blue crosses show the CO and dust measurements from PHIBSS at z < 3 (Tacconi et al. 2018) and additional sources from the literature (see text), respectively. All samples have been restricted to galaxies with M_stars = 10^{8.5−10 5} M_⊙ to match the range spanned by REBELS galaxies. The solid blue, dashed magenta, and dot-dashed black lines represent the prescriptions for the scaling relations computed for the median mass of the REBELS sample, M_stars = 10^{9 75} M_⊙ and z = 7, from Scoville et al. (2017), Tacconi et al. (2018) and Liu et al. (2019), respectively.