Understanding the molecular arms race between bacteriophages (phages) and their bacterial hosts is critical for advancing microbiome research, antimicrobial strategies, and phage therapy. A key challenge lies in the vast number of predicted proteins from phage and bacterial genomes that remain functionally uncharacterized. Functional annotation of these proteins based on their sequence and structure is essential to uncover novel components of bacterial defense systems and phage-encoded anti-defense mechanisms. We can identify unknown effectors, inhibitors, and modulators involved in host-phage interactions through this approach. This project aims to deepen our understanding of microbial immunity and co-evolution.