Gas-to-stellar mass ratio (μ_gas = M_gas/M_⋆), gas depletion time (τ_gas = M_gas/SFR), and starburstiness (R_SB) as a function of stellar mass (left column) and redshift (right column). μ_gas and τ_gas are scaled relative to field galaxy levels (μ_{gas,  scale}, τ_{gas,  scale}), accounting for the stellar masses, redshifts, and starburstiness of each galaxy. The red circles represent galaxies detected in CO or dust continuum in the NICE protoclusters, including the eight in the COSMOS field (Sillassen et al. 2024), LH-SBC3 (Zhou et al. 2024), RO1001 (Kalita et al. 2021), and CL J1001 (Wang et al. 2018), while red squares and dots indicate the 3σ upper limits of those detected in the FIR and the rest of the cluster galaxies. Two additional starbursting protoclusters at z ≳ 4, SPT2349-56 (Hill et al. 2022) and Distant Red Core (Long et al. 2020), are shown in cyan. Field galaxies from Kaasinen et al. (2019), Boogaard et al. (2020), Frias Castillo et al. (2023) are represented as green triangles, with the molecular gas content derived from CO(1–0) emission lines. The black dashed lines denote the positions of field galaxies; the gray shading indicates the uncertainties.