The IRAG2 gene (Inositol 1,4,5-trisphosphate receptor-associated GCAP2) encodes a protein which plays several critical roles, particularly in immune response and cellular processes. Here’s more detailed information based on your requirements:

### 1. Associated Genes
While the NCBI and UniProt summaries did not provide specific genes directly associated with IRAG2, it is worth noting that similar genes in terms of function or expression within the immune system may include:

- **ITPR3 (Inositol 1,4,5-trisphosphate receptor type 3):** IRAG2 may play a role in taste signal transduction through this receptor.
- **TAP (Transporter associated with antigen processing):** Although TAP is mentioned in relation to IRAG2's function, direct associations are not specified, but it is integral to antigen presentation.
- **Other members of the LINC complex:** This would include genes like **SUN1**, **SUN2**, **KASH domain proteins**, which are important in maintaining nuclear shape and cellular organization.

### 2. Aging and Age-Related Diseases
While specific literature directly connecting IRAG2 to aging or age-related diseases may be limited, its role in cellular processes suggests potential relevance. For example:

- **Immunosenescence:** Since IRAG2 is involved in immune function, changes in its expression or signaling pathways may influence immune system aging.
- **Cellular Integrity:** Its involvement in maintaining nuclear shape and interaction with microtubules could connect it to age-related cellular dysfunction and diseases such as cancer.

Further investigation into aging studies and databases may yield more connections; however, specific findings directly linking IRAG2 to aging remain scarce.

### 3. Drug Interactions
As of now, there is no well-established list of drugs or drug classes known to specifically interact with IRAG2. However, given its role in immune function and cellular signaling, indirect interactions may exist through:

- **Antineoplastic agents:** These might influence pathways involving antigen presentation and immune response.
- **Immunomodulatory drugs:** Since IRAG2 is involved in lymphoid cell regulation, drugs that modulate the immune system could potentially influence its activity.

For precise drugs that affect IRAG2, insight from more detailed pharmacogenomic studies or literature reviews may be necessary.

### 4. Pathways and Biological Processes
IRAG2 is implicated in several biological processes, including:

- **Antigen presentation:** Contributing to the delivery of peptides to MHC class I molecules.
- **Signal transduction:** Involved in taste perception and potentially other pathways.
- **Fertilization:** Plays a role in pronucleus congression and fusion, indicating its involvement in reproductive biology.
- **Maintaining cellular integrity:** Participation as a component of the LINC complex and interaction with the cytoskeleton suggests a role in overall cellular architecture and nuclear shape maintenance.

These pathways emphasize the gene's multifaceted role in cellular and physiological processes.

In summary, IRAG2 stands as an important gene with various functions primarily in the immune system and cellular integrity, while associations with aging, drugs, and other genes warrant further exploration in specific contexts.