Provided are antibodies or antigen-binding fragments specific for CD44V6 or v9 epitope which comprises or consists essentially of SEQ ID NO:19 or 43. Also provided are antibody-drug-conjugate (ADC), other derivatives comprising the antibodies or antigen-binding fragments, nucleic acid molecules encoding the same, methods of making the same, pharmaceutical compositions comprising the same, and using of the same in treating or diagnosing diseases thereof.
