| AD families | AD genes | Defense system | CLAN ID | Phages/MGEs | References | Description |
|---|---|---|---|---|---|---|
| ardk | ardk | restriction-modification (RM) | CLAN068 | Plasmid pKM101 | PMID: 8393008 | ArdK and ArdR likely serve as ardKR-dependent regulatory system that controls the expression of ArdA and ArdB. |