Spearman’s rank correlation coefficients between the parameters of mid-IR PDFs of intensity at 21 μm and global galaxy properties. Stronger positive (negative) correlations are indicated in green (pink). We present rank correlations among the most important observation-specific parameters (galaxy inclination i, distance d), intrinsic properties (SFR surface density Σ_SFR, stellar mass surface density ﹩{{\rm{\Sigma }}}_{{M}_{* }}﹩, H I mass surface density ﹩{{\rm{\Sigma }}}_{{M}_{\mathrm{HI}}}﹩, and CO luminosity surface density ﹩{{\rm{\Sigma }}}_{{L}_{\mathrm{CO}}}﹩), and extrinsic properties (average SFR, total stellar mass M _*, H I mass M _HI, CO luminosity L _CO, average [O/H], and effective radius R _e ), as well as the H II region luminosity function slopes α from Santoro et al. (2022), with PDF parameters (H II region power-law index m, diffuse lognormal mean μ and dispersion σ) and region-wise flux contributions (median intensity I ₅₀ and percent of total flux in field of view for centers, H II regions, and the diffuse ISM).