FIELD: biotechnology; medicine.SUBSTANCE: novel polypeptide sequences capable of inhibiting RAS-GTPase activity, including a functional fragment and a transport sequence, wherein the functional fragment includes the amino acid sequence SEQ ID NO: 1 or fragment SEQ ID NO: 2. Also described is use of said polypeptide for inhibiting the MAPK/ERK signaling pathway, as well as preparing a drug for treating lung cancer.EFFECT: disclosed are polypeptides for treating oncological diseases.7 cl, 30 dwg, 3 tbl, 7 ex