U1-59, the antibody-drug conjugate (3), the antibody-drug conjugate (10), or the antibody-drug conjugate (13) was evaluated as the antibody or the antibody-drug conjugates. The cells of each group were reacted with a primary antibody dilution for 45 minutes on ice and then washed with a FACS buffer. Further, 100uL of a FACS buffer or a reaction solution of a secondary antibody diluted 1/100 (phycoerythrin (PE)-coupled anti human antibody, Dianova GmbH #709-116-149) was added thereto. The cells were treated for 45 minutes on ice in the dark and then washed with a FACS buffer, and dead cells were excluded using a FACS buffer or a FACS buffer supplemented with 7-aminoactinomycin D (7AAD, Sigma-Aldrich Co. LLC, #A9400, 1.1 ug/mL). The equilibrium binding affinity (KD) and the maximum binding strength (Bmax) were calculated using GraphPad Prism software (version 5.04 for Windows (R) (one site-specific binding)).