(f) Left: Scheme of long-range interactions between Sμ-Sα elements in the IgH locus before and after AID activation. Right: Representative gel picture of the 3C assay detecting the Sμ-Sα interaction in WT or Samhd1 KO CH12F3-2A cells with or without CIT stimulation for 24 h. Gapdh was amplified as a loading control. 