The major difference is that the existing decoy closely resembles the natural ACE2 receptor, and has not been mutated to bind as tightly as possible to SARS-CoV-2, while sACE2.v2.4 has.

Jonathan Parkinson, Ryan Hard, Wei Wang. The RESP AI model accelerates the identification of tight-binding antibodies. Nature Communications, 2023; 14 (1) DOI: 10.1038/s41467-023-36028-8 ...

That insight led the team to make cresomycin’s 10-membered ring. Structural biology studies show that cresomycin binds tightly to several bacterial ribosomes, including drug-resistant ones.

When Office 12 debuts next year, the default "save-to" file format of the applications will be XML, or at least a version that Microsoft is calling Microsoft Open XML Formats.