QRT-PCR analysis of cyclin D1 mRNA levels in MMs. QRT-PCR analysis of cyclin D1 was performed relative to the TBP housekeeping gene and results are depicted as ratio of cyclin D1/TBP transcript numbers. Three distinct groups of MMs with respect to cyclin D1 levels can be identified. Note for comparison the cyclin D1 levels in a group of 23 cases of mantle cell lymphoma (MCL), the KMS12 MM cell line harboring a t(11;14)(q13;q32) translocation, and the A431 squamous cell carcinoma cell line harboring a 11q13 amplification. The horizontal line indicates the cutoff value for altered cyclin D1 expression as described in “Patients, materials, and methods.”