### CAPN15 Gene Overview

**Gene Symbol**: CAPN15  
**Function**: Encodes a protein with zinc-finger-like repeats and a calpain-like protease domain, which may act as a transcription factor or RNA-binding protein, potentially influencing protein-protein interactions during visual system development. 

**Expression**: CAPN15 is widely expressed in various tissues, with particularly higher expression levels noted in the brain.

### 1. Associated Genes
CAPN15 has been implicated in relationships with several genes involved in neuronal development, signaling pathways, or cellular stress responses. Specific associated genes may include:

- **CAPN1**: Another calcium-regulated cysteine protease.
- **CAPN2**: Similar to CAPN15, involved in skeletal muscle and other cellular processes.
- **CNR1**: The cannabinoid receptor might also be involved in signaling pathways associated with CAPN15.

The specific interactions can vary across studies, and other candidates may involve genes related to visual processing and neuronal differentiation.

### 2. Aging and Age-related Diseases
As of October 2023, the specific role of CAPN15 in aging or age-related diseases is not well-documented. However, calpain proteases have been implicated in various neurodegenerative diseases due to their role in proteolysis and cellular signaling. Potential links to conditions like Alzheimer's disease or other age-related cognitive decline may arise, as disruptions in protein homeostasis often occur with aging. Further research is necessary to clarify any direct associations between CAPN15 and aging processes or associated diseases.

### 3. Drug Interactions
Current data does not provide specific drugs or drug classes that interact directly with CAPN15. However, given the protein's role in proteolysis and signaling, it is conceivable that certain drugs targeting calpain activity or related pathways may indirectly influence CAPN15's effects. More targeted research or drug development may elucidate potential interactions.

### 4. Pathways and Biological Processes
CAPN15 is involved in several biological pathways and processes, including:

- **Regulation of Gene Expression**: Acting as a transcription factor, it might influence the transcription of target genes.
- **Neuronal Development**: Participates in the differentiation and development of neuronal cells, particularly in the context of the visual system.
- **Protein-protein Interactions**: Facilitates interactions between proteins, which is critical during various cellular processes such as signaling and forming complex structures.
- **Calpain-mediated Pathways**: As a calpain-like protease, it may partake in calcium-dependent processes, modulating signaling pathways during cellular stress responses.

**Note**: While CAPN15 stands out for its potential roles in neuronal health, ongoing research may better define its functions and clinical implications, particularly in the context of diseases and aging.