MGI:9782410-25% of B-cell plasmacytomas have (6;15) translocations that bring Myc into proximity with Igk. The Chr 15 breakpoint occurs at Pvt1, located >72 kb distal to Myc. These tumors have an activated Myc. In addition, some T-cell lymphomas have been shown to have proviral inserts at the Pvt1 locus.