Test Details: Immunohistochemical testing is carried out on biopsy/resected tissue specimen. This testing helps to identify specific antigens (proteins) within tissue sections utilizing an antigen-specific antibody. Cyclin D1 (also known as bcl-1) is a cell cycle protein involved in the regulation of cyclin-dependent kinases of the first gap phase (G1) of the cell cycle. Its overexpression is associated with mantle cell lymphoma. It is also variably expressed in Inflammatory pseudotumor (myofibroblastic tumour), hairy cell leukaemia and multiple myeloma.