Serotonin binds preferentially to disordered phase in simulations and acyl chain order parameters of ordered phase are not affected, while its signal originates mostly from ordered state in NMR experiments. Unresolved Accumulation of the ionizable MC3-lipids Ionizable MC3-lipids, used in lipid-nanoparticle formulations for vaccines, accumulate in the bilayer center when the CHARMM36 force field is used, while Slipids shows almost no accumulation. Unresolved for charged residues and their interactions with lipid headgroups. While sodium and calcium ion binding to membranes with various compositions have been quantitatively evaluated using lipid headgroup order parameter data, such comparison is not available for proteins or amino acids interacting with membranes. The evaluation of lipid-protein interactions has focused on comparing hydrophobicity scales, NMR data or crystallized lipid-protein complexes. While hydrophobicity scales are often qualitatively reproduced by MD simulations, and proteins are usually oriented reasonably in membranes in these studies, charged residues often appear as outliers or potential sources of discrepancies with experiments. Also, the partitioning of small neutral molecules seems to agree with experiments qualitatively, 81 but experimental data is more scarce for charged molecules, and a systematic comparison of MD simulations with experiments is not available. In conclusion, we see that many controversial results from MD simulations originate from the description of polar and charged molecules or molecular groups, including water, and particularly their interactions with lipids. Therefore, we focus in the following on the effects of water models and electronic polarizability on interactions involving lipids. Other force field inaccuracies and issues related to simulation methodology, such as insufficient sampling or algorithms, are left for other accounts.