Pep1-DNP conjugate 9 is a functionalized peptide which is composed of the DNP-Hapten and the FGFR1 binding peptide. Pep1-DNP conjugate 9 exhibits good affinity to FGFR1 with K D of 5.01 μM. Pep1-DNP conjugate 9 recruits anti-DNP antibodies to the surface of FGFR1-positive cells, inhibits the FGF2-induced proliferation in rat skeletal myoblast cells, and induces apoptosis. Pep1-DNP conjugate 9 exhibits antitumor efficacy in mouse models.