MCT-1 protein levels are increased in primary samples from a subset of patients. (A) Western blotting was carried out to detect MCT-1 and PCNA proteins from grossly involved lymph nodes of patients with newly diagnosed DLBCL. Seven of 13 specimens displayed elevated MCT-1 protein levels and were shown to correlate with increased PCNA levels. All 4 transformed lymphomas in our group demonstrated strong signals for MCT-1 protein (samples 3, 8, 9, and 11). (B) Ten normal lymph nodes examined had no detectable MCT-1 or PCNA. The Jurkat cell line served as a positive control for MCT-1 and PCNA protein expression.