Abundance ratio of CH₃OCH₃ with respect to HCOOCH₃ in HOPS-108 compared to other isolated hot corinos. In the top plot, the sources are separated according to their class, with no particular order within a given class. In the middle and bottom plots, the abundances are as a function of HCOOCH₃ and CH₃OCH₃ column densities, respectively. The same sources from Fig. 4 are used, including B1-bS (Marcelino et al. 2018).