Residue specificity and enrichment of sequons of 10 protease-specific substrates, including (A) caspase-1, (B) caspase-3, (C) caspase-6, (D) granzyme B (Homo sapiens), (E) granzyme B (Mus musculus), (F) thrombin, (G) matrix metallopeptidase-2, (H) matrix metallopeptidase-3, (I) calpain-1 and ( J) calpain-2.