In the future, as the relative contributions of each individual AID/APOBEC3 enzyme to immunity and cancer in different contexts become clearer, it will be important to test the hypothesis that catalytic pocket breathing differences among the AID/APOBEC3 family members impact their relative contributions, and to understand the extent to which this novel built-in safety switch is intertwined with other regulatory mechanisms, such as perhaps being modulated by aforementioned extrinsic binding partners, oligomerization or post-translational modifications. Here, AICDA is linked to cancer.