The CCDC91 gene, which stands for "Coiled-Coil Domain Containing 91," has several functional implications and associations. Below is a detailed overview based on your request:

### 1. Associated Genes:
While specific associations can vary, the CCDC91 gene is thought to interact with several other genes involved in lysosomal function and membrane trafficking. Notably, it cooperates with:
- **GGA (Golgi-localized γ-ear-containing ARF-binding proteins)**: These proteins are critical for the sorting and transport of proteins from the trans-Golgi network to lysosomes.
- **ARF (ADP-ribosylation factor)**: A family of small GTP-binding proteins that play a significant role in vesicle formation and trafficking.
- **Various lysosomal hydrolases and their receptors**: Important for the targeting of these enzymes to lysosomes.

### 2. Aging and Age-Related Diseases:
CCDC91 has not been extensively routed in literature explicitly focusing on aging or age-related diseases; however, due to its vital role in lysosomal trafficking and protein sorting, any dysfunction in this pathway could potentially contribute to:
- **Neurodegenerative diseases**: Impaired lysosomal function is often linked to conditions such as Alzheimer's disease, Parkinson's disease, and other neurodegenerative disorders.
- **Age-related cellular senescence**: Disruption in normal cellular function and trafficking pathways could have implications in cellular aging processes.

Further research could elucidate specific connections between CCDC91 and age-related conditions.

### 3. Drug Interactions:
Currently, there is limited direct information regarding specific drugs or drug classes that target or interact explicitly with the CCDC91 gene or its protein product. However, generally related drugs affecting lysosomal function or trafficking may indirectly influence the pathways involving CCDC91. Drugs that impact lysosomal activity or are known to have effects on Golgi function might include:
- **Lysosomal enzyme replacement therapies**: Used in conditions like Gaucher's disease.
- **Mannose-6-phosphate analogs**: Can influence the targeting of lysosomal enzymes.
  
Further exploration into pharmacogenomics may reveal drug-gene interactions in specific populations.

### 4. Pathways and Biological Processes:
CCDC91 is involved in several relevant biological pathways, including:
- **Golgi to lysosome transport**: As highlighted, CCDC91 plays a crucial role in the transport of proteins from the Golgi apparatus to lysosomes.
- **Lysosomal transport**: Essential for maintaining lysosomal function and cellular waste management.
- **Protein sorting and trafficking**: Implicates broader roles in secretory pathways, endosome function, and autophagy.

In summary, CCDC91 is integral to membrane trafficking in cells, with implications for lysosomal function and potentially age-related diseases, although direct links require further investigation. Its partner genes and associated biological processes outline critical roles in cellular logistics, maintaining physiological homeostasis.