The CBASS system stands for cyclic oligonucleotide-based antiphage signaling systems :ref{doi=10.1016/j.molcel.2021.10.020}. There are four types and multiple subtypes of characterized CBASS trans membrane systems. Activation of this system results in cell death to prevent phage replication. This system has a shared ancestry with the cGAS-STING innate immune pathway in animals :ref{doi=10.1038/s41564-020-0777-y}
## Molecular mechanism
CBASS effector proteins limit phage propagation through membrane disruption. When CBASS is activated, Cap15 spreads throughout the cell and causes the inner membrane to rupture :ref{doi=10.1016/j.molcel.2021.10.020}
## Example of genomic structure
A total of 4 subsystems have been described for the CBASS system.