Diagram of all known planets with masses from radial velocity measurements up to 13 M_J and radii from transit photometry with 30% and 10% uncertainties or lower in mass and radius, respectively. Planets with T_eq ≥ 1800 K are colour-coded with T_eq, and the rest are plotted in light grey. In total, there are four planets (including TOI-2196 b) with radii between 3 and 5 R_⊕ in this diagram that are identified as hot Neptune desert planets (cf. Fig. 9). TOI-2196 b is marked with a red star symbol and the three additional planets with black diamonds. Solar system planets are marked with brown squares. Interior models from Zeng et al. (2019) are plotted as listed in the legend. The 100% water line is for a planet with condensed water phases.