CD4 and Miyoshi myopathy: In vitro studies have also shown that direct contact with MM cells is able to induce the development of CD4+CD25+FoxP3+ Tregs from an initial population of CD4+CD25−FoxP3− cells, mediated by an inducible T-cell co-stimulator (ICOS) on T cells and their ligands (ICOS-L) expressed on MM cells [32].