A peptide is disclosed that has an amino acid sequence selected from X1-X2-X3-Gln-Leu-Met-Leu-Cys-Val-Leu-X4-X5-X6 (SEQ ID NO: 3), X1-X2-X3-Gln-X7-Met-X10-Cys-Val-X11-X4-X5-X6 (SEQ ID NO: 4), Ile-Ser-Phe-Gln-Leu-Met-Leu (SEQ ID NO: 5), Leu-Cys-Val-Leu-Asp-Tyr-Phe (SEQ ID NO: 6), X1-X2-X3-Gln-Leu-X8-Leu-X9-Val-Leu-X4-X5-X6 (SEQ ID NO: 7), X1-X2-X3-Gln-Leu-X8-Leu-X9-Val-Leu-X4-X5-X6 (SEQ ID NO: 7), X1-X2-X3-X12-Leu-Met-Leu-Cys-X13-Leu-X4-X5-X6 (SEQ ID NO: 10), Gln-X7-Met-X10-Cys-Val-X11 (SEQ ID NO: 11), Gln-Leu-X8-Leu-X9-Val-Leu (SEQ ID NO: 12), X12-Leu-Met-Leu-Cys-X13-Leu (SEQ ID NO: 13), Asp-Leu-Val-Ile-Ser-Phe-Gln-Leu-Met-Leu-Cys-Val-Leu-Asp-Tyr-Phe-Ile-Lys (SEQ ID NO: 14) and retro-inverso peptides thereof. The peptides disclosed herein may be used to treat liver cancer, lung cancer, breast cancer, pancreatic cancer, or brain cancer.