CD5 is a phenotypic marker of B cell lymphoproliferative diseases.
CD5 positive B cell population is present in several autoimmune disorders, including diabetes mellitus (insulin-dependent), rheumatoid arhrytis, or Sjögren syndrome.
Expression of CD5 regulates the responsiveness of human T cell to interleukin-1.
B cell lymphomas are relevant for CD5 antigen detection in related malignancies.