Thank you for that Neuroproblem. Among other things I am an immunologist but that part of my research is concerned with innate immunity (the complement system).

I realise that my post was somewhat simplified but I hope that I did not confuse anybody.

Two things that you wrote struck me:

"primary igm first, than it switches depending on the situation, to prevent autoimmunity [emphasis added]"

My understanding of heavy chain class switching (aka isotype switching) is that it is controlled by cytokines made by Th1, Th2 and Treg cells - as far as I know it does not involve autoimmunity - can you shed some light on this?

"For cancer, it is usually the immature, or stem cell stages that will become myeloma"

As I understand it, myeloma arises from transformation of plasma cells, usually in the bone marrow. I may be wrong but I do not think that plasma cells are "immature" in the B cell lineage. Would you like to comment on this?