Our data suggest at least four such patterns (Fig. 5e): (1) where APOBEC plays a major role during all evolutionary phases, including cancer initiation, and where AID contribution is minimal; (2) where APOBEC is not involved in any phase; (3) where AID is active only during the very early phase of cancer initiation; and (4) where AID is the main mutational process since the very first phases of cancer development and still plays a role in the late subclonal diversification. The gene discussed is AICDA; the disease is cancer.