Relations between stellar and dark matter properties for the simulated galaxies from IllustrisTNG50. The figure is organised as a matrix, where each row corresponds to a stellar quantity (from top to bottom: ${\mathrm{\Sigma }}_{1,\mathrm{kpc}}^{\mathrm{spec}}$, M_* and R₁) and each column corresponds to a dark matter halo property (from left to right: λ, $M_{200}^{\mathrm{DM}}$, and $c_{200,\mathrm{c}}^{\mathrm{DM}}$). BL, BI, and BD galaxies are shown as green circles, blue isodensity contours, and orange diamonds, respectively. On the top and right panels, histograms of the corresponding quantities are shown for BL and BD galaxies, where vertical lines represent the mean of each distribution.