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).

Ivy: Dull dull dull dull dull dull dull dull dull dull dull dull dull. Posey: No, you're not. Ivy: Not me! The flowers. I planted all these carnations months ago and I thought they'd be colourful ...