He took Ben to China for stem cell-like treatments, and later helped hundreds of people do the same, believing it would help them. The unproven procedure could have killed Ben. It didn't -- but it ...

Somatic hypermutation (SHM) of immunoglobulin variable (V) regions modulates antibody-antigen affinity is initiated by activation-induced cytidine deaminase (AID) on single-stranded DNA (ssDNA).