Pseudogenes are ubiquitous and abundant in genomes. Pseudogenes were once called "genomic fossils" and treated as "junk DNA" several years. Nevertheless, it has been recognized that some pseudogenes play essential roles in gene regulation of their parent genes, and many pseudogenes are transcribed into RNA. Pseudogene transcripts may also form small interfering RNA or decrease cellular miRNA concentration. Thus, pseudogenes regulate tumor suppressors and oncogenes. Their essential functions draw the attention of our research group in my current work on heat shock protein 90: a chaperone of oncogenes. The paper reviews our current knowledge on pseudogenes and evaluates preliminary results of the chaperone data. Current efforts to understand pseudogenes interactions help to understand the functions of a genome.