Left panel: IR luminosities, L_IR, vs. CO(1-0) line luminosities, ﹩{L}_{\mathrm{CO}(1-0)}^{{\prime} }﹩, for CO(1-0) detected galaxies in CLJ1001. The solid and dashed lines represent the scaling relation for field MS and strong SB galaxies (ΔMS ∼ 10), respectively (Sargent et al. 2014). The field galaxy sample includes both MS and SB galaxies drawn from the compilation by Sargent et al. (2014), and a sample of z ∼ 1 SB galaxies by Silverman et al. (2015). We also include a few recent studies of cluster galaxies at z ≳ 1.5, which have either CO(2–1) (Stach et al. 2017; Noble et al. 2017) or CO(1-0) (Rudnick et al. 2017) measurements. Right panel: SFE, as indicated by the ratio between L_IR and ﹩{L}_{\mathrm{CO}(1-0)}^{{\prime} }﹩, vs. ΔMS for galaxies in CLJ1001. The best-fit relation for field galaxies and its associated 1σ scatter are also shown (Magdis et al. 2012). A large variety of SFE for cluster galaxies is observed.