Logarithm of the ratio between average HI mass of dusty QGs and equivalent HI mass in MS galaxies at the same stellar mas according to B25, plotted against the median overdensity δ for each galaxy bin. A dashed horizontal line at y = 0 indicates the HI content of SFGs. Filled purple squares mark the HI estimates from stacking dusty galaxies in lower-density (δ < 1) and in higher-density (δ > 1) bins. Empty red stars represent spiral and irregular galaxies divided into the two separate δ bins. Empty teal circles indicate spheroid galaxies in the same δ bins.