PDCD1 and myocarditis: Douglas and others have carried out T-cell receptor next-generation sequencing (CDR3 region, the antigen-binding portion of the T-cell receptor beta chain), indicating that patients with PD-1/PD-L1 inhibitors related myocarditis have their own high-frequency T-cell receptor sequences among cardiac, skeletal muscle, and tumor tissue (Johnson et al., 2016).