CD19 and diffuse large B-cell lymphoma: It is used to treat adult patients with relapsed or refractory large B-cell lymphoma (including diffuse large B-cell lymphoma not otherwise specified, primary mediastinal large B-cell lymphoma, high-grade B-cell lymphoma, and diffuse large B-cell lymphoma from follicular lymphoma) who have previously received at least two lines of systemic therapy.341–345Relmacabtagene Autoleucel Injection is an autologous immune cell injection, prepared from autologous CD19-targeted CAR-T cells genetically modified by a lentiviral vector carrying the CD19 CAR gene.