To determine whether AID can target mtDNA, we used multiple B cell lines with constitutive AID expression, including human chronic lymphocytic leukemia line Mec1, human Burkitt lymphoma line Ramos and Ramos‐A23, a Ramos derivative that expresses high levels of AID [21, 26]. The gene discussed is AICDA; the disease is B-cell chronic lymphocytic leukemia.