The HHIPL1 gene, or Hedgehog Interacting Protein-Like 1, is an interesting member of the glucose/sorbosone dehydrogenase family. Below, I elaborate on the aspects you've requested related to HHIPL1.

1. **Associated Genes**:
   - Although specific associations are not always listed in summary data, related genes involved in similar pathways or functions may include other members of the HHIP family as well as those involved in folate metabolism, such as the **MTHFR** gene (methylenetetrahydrofolate reductase). Additional genes potentially associated with HHIPL1 may include **GAD1** (glutamic acid decarboxylase 1), involved in neurotransmitter pathways.

2. **Aging and Age-Related Diseases**:
   - Current literature has suggested that folate metabolism is linked to aging and several age-related diseases, such as cardiovascular diseases and certain types of cancer. Variations in genes involved in folate metabolism can influence homocysteine levels, which are associated with cognitive decline. Specifically, dysregulation of folate and related compounds can affect neurodegenerative diseases like Alzheimer's.

3. **Drug Interactions**:
   - Specific drug interactions with the HHIPL1 gene have not been explicitly detailed in the primary databases. However, drugs and compounds that influence folate metabolism, such as **methotrexate** (a folate antagonist used in cancer treatment) or **folic acid supplements**, could have indirect interactions through their common biochemical pathways.

4. **Pathways and Biological Processes**:
   - The HHIPL1 gene is involved in multiple biological processes, particularly those related to metabolic pathways, specifically:
     - Folate metabolism, which is essential for DNA synthesis, repair, and methylation processes.
     - Regulation of Hedgehog signaling pathways due to its relation to the HHIP family.
     - Overall energy metabolism by participating in the glucose/sorbosone dehydrogenase pathway.

**Note**: It is important to consult the latest research literature for updates on gene function and its associations with diseases or interactions since the field of genetics and bioinformatics is continuously evolving.