In contrast, all subsets of PD-1-ICOS+ Tfh (PD-1-ICOS+ Tfh1, PD-1-ICOS+ Tfh2, and PD-1-ICOS+Tfh17) in the PB samples of patients with MM showed a gradual increase after chemotherapy. The gene discussed is ICOS; the disease is Miyoshi myopathy.