| AD families | AD genes | Defense system | CLAN ID | Phages/MGEs | References | Description |
|---|---|---|---|---|---|---|
| Stp | Stp | restriction-modification (RM) | CLAN012 | T4 of E. coli | PMID:7791212 | Stp has been implicated with activation of the anticodon nuclease and inhibition of EcoprrI restriction. |