The SNORA20B gene, also known as small nucleolar RNA (snoRNA) 20B, encodes a member of the small nucleolar RNA (snoRNA) family, which are involved in the chemical modification of other RNAs, particularly ribosomal RNAs (rRNAs) and small nuclear RNAs (snRNAs).

### 1. Associated Genes
While the NCBI and UniProt summaries may not extensively list associated genes, snoRNAs often interact with various genes involved in RNA processing, ribosome biogenesis, and other post-transcriptional modifications. Some snoRNAs can co-regulate or depend on the expression of the following general classes of genes:
- Ribosomal proteins (r-proteins)
- RNA modification enzymes (methyltransferases)
- Components of the spliceosome 
- Other snoRNAs or small nuclear RNAs

Specific associations may be discovered through gene expression studies that point to co-regulation or physical interactions with genome-wide association studies (GWAS).

### 2. Aging and Age-Related Diseases
Data regarding the direct involvement of SNORA20B in aging or age-related diseases is limited. However, it is known that disturbances in snoRNA expression and function can lead to misregulation of rRNA and other non-coding RNAs, which could have implications in:
- Cellular senescence
- Age-associated decline in cellular function
Alterations in snoRNA expression profiles have been implicated in certain types of cancers, which can be age-related, but specific links to SNORA20B would require further exploration in the context of research literature.

### 3. Drug Interactions
Currently, there are no well-documented specific drugs or drug classes known to directly interact with SNORA20B. However, considering its role in RNA modification, changes in the expression of SNORA20B may influence the pharmacodynamics of drugs that target RNA-related pathways. Drug responses could be impacted indirectly through the regulation of targets affected by the snoRNA's activity; for example, drugs affecting RNAs involved in translation could have downstream effects traced back to snoRNA activities.

### 4. Pathways and Biological Processes
SNORA20B is primarily involved in:
- **RNA modification**: Functions in the biogenesis and maturation of rRNA through methylation processes.
- **Ribosome biogenesis**: Plays a critical role in the assembly of ribosomes and ensuring the proper function of the protein biosynthesis machinery.
- **SnRNP assembly**: May play a role in the assembly of small nuclear ribonucleoproteins, which are vital for pre-mRNA splicing.
- **Nucleolar organization**: Involved in maintaining the structure and function of the nucleolus where ribosome synthesis takes place.

To derive a complete understanding of SNORA20B’s implications in various biological contexts, a thorough investigation involving experimental data would be required, particularly targeting its expression patterns in age-related or disease contexts.