I believe that the most common antibody switch is from IgM to IgG.
Class switching occurs by a mechanism called the class switch recombination binding. It is a biological mechanism that allows the class of antibody produced by an activated B cell to change during a process known as isotype or class switching. The mechanism changes a B cell's production of antibodies from one form to another, such as from the isotype IgM to the isotype IgG.
every cell in our body contains Dna
the radiations that are used to treat cancers are of the gamma type. primarily emitted from cobalt-60 (a radioactive isotope). and it is more controlled than other radiation exposures. i.e. solar radiation which is not controlled.
hope that this helps.