We can preclude a possibly inaccurate thickness of the membrane as the cause for the WALP16 TM instability: due to its coarseness, the Martini 3 DMPC is the same model as the one representing DLPC, and yields a thickness about 2 Å thinner than experimentally reported (3.4 nm vs 3.67 nm; see Supplementary Figure ). Being somewhat thinner, a Martini DMPC membrane is, if anything, more accommodating of WALP16's negative size mismatch than if it better matched the experimental thickness (moreover, the mismatch is further reduced by the additional thinning of lipids in the peptide's vicinity).