Production and selection of innovative monoclonal antibodies that can be used for ADC through hybridoma and phage display technologies, recombinant expression and humanization of these antibodies, determination of the epitopes to which the antibodies bind on the target proteins, and verification of the binding affinity and specificity of the antibodies to target cells and target tissues; construction and optimization of antibody expression vectors, construction and optimization of target protein expression vectors, production and preliminary purification of antibodies and target proteins, and verification of their structures and functions via transient antibody expression; establishment of highly productive antibody stable expression cell lines, and verification of their monoclonality, sta