For CSR to unfold, AID and the whole CSR machinery must be targeted to the S regions that are set to undergo recombination to introduce DSBs, the resolution of which leads to S–S DNA recombination – dysregulation of AID expression and targeting has been associated with chromosomal translocations, lymphomagenesis and autoimmunity [19]–[22]. The gene discussed is AICDA; the disease is Autoimmunity.