To further investigate karyotype heterogeneity in CIN lymphomas, we set up cohorts of Mps1f/f; Lck-Cre+, Mps1f/f; p53f/f; Lck-Cre+ and Mps1f/f; p53f/+; Lck-Cre+ mice, and Lck-Cre− mice as controls. The gene discussed is LCK; the disease is lymphoma.