Immunodetection of Cyclin Dl is useful for separating mantle cell lymphomas (+) from SLL's and small cleaved cell lymphomas (-). Cyclin D , one of the key cell cycle regulators, is a putative proto-oncogene overexpressed in a wide variety of neoplasms. Cyclins govern transitions through distinct phases of the cell cycle by regulating the activity of the cyclin dependent kinases. ln mid to late Gl, Cyclin Dl shows maximum expression following growth factor stimulation.
Fixed-embedded human mantle cell lymphoma