Intriguingly, 3 of 6 LPD mice shared an obvious stereotyped subset with highly homologous IGHV-IGHD-IGHJ gene rearrangement, displaying significant similarity on the variable domain heavy chain CDR3, a feature found in human patients with CLL,49 suggesting a common antigen for the clonal expansion and pathological relevance of the PRC2-mutated CLL-like model, analogous to the corresponding human disease (Table 1). The gene discussed is IGHD; the disease is B-cell chronic lymphocytic leukemia.