CD19 and neoplasm: Here, we acquired Nbs that specifically bind human CD19 and CD20, optimized T cell activation and expansion conditions, and generated CD19 Nb CAR-T, CD20 Nb CAR-T and Bispecific Nb CAR-T cells that with the ability to accurately recognize tumour cell, followed by activation and proliferation, and these Nb CAR-T cells could also effectively protect against tumour cells in vitro.