FURIN and anthrax infection: Leveraging Elliott Shaw’s success with peptidyl CMKs and the furin crystal structure, several cell-penetrant peptide inhibitors, including substrate-based inhibitors containing the H5N1 cleavage site and poly-D-arginine-based peptides, have been developed and shown to prevent the processing of anthrax PA in cellulo and to protect mice from anthrax toxemia in vivo [97,98,99,100,101].