Overexpression of cyclin D1 may occur through multiple mechanisms, including chromosomal translocation events (e.g. Mantle cell lymphomas (Bigoni et al, 1996)), gene amplification (common in breast (Buckley et al, 1993) and oesophageal cancers (Jiang et al, 1993)), and defects in protein processing or transport (Gladden and Diehl, 2005). Here, CCND1 is linked to mantle cell lymphoma.