CD4 and mantle cell lymphoma: More recently, Khodadoust et al. recovered peptides representing somatic mutations in Ig heavy and light chain genes from the peptidomes of both class I and class II molecules in 17 primary mantle cell lymphomas (MCL) and two MCL cell lines, and detected circulating functional CD4+ T cells specific for one Ig neoantigen that could kill autologous lymphoma (140).