H1 genes are commonly mutated in follicular lymphoma, Waldenström’s macroglobulinemia, and diffuse large B-cell lymphoma (DLBCL) in a manner that is predicted to be a loss-of-function, and reduce the total dosage of H1 proteins.32,47–50 The potential relevance of this observation has been recently evaluated in a study showing that germinal center B cells of H1.2 and H1.4-deficient mice re-express stemness genes. This evidence concerns the gene H1-5 and Waldenstrom macroglobulinemia.