From Omics.org

Abnormality of specific ribosomal proteins causes genetic diseases and tumorigenesis. Also, ribosomal proteins appear to have roles in addition to those in the translation machinery (extraribosomal functions). Mutants of model eukaryotic organisms have revealed that many ribosomal proteins are essential for cell viability. However, the precise structure, functional role, and regulation of each ribosomal protein in the eukaryotic ribosome are largely unknown.