Pharmaceutical compositions, systems and methods for treating a non-small cell lung cancer (NSCLC) solid tumor comprising a population of tumor cells are described. In some aspects, administering a pharmaceutical composition comprising a therapeutic amount of a polypeptide having the amino acid sequence YARAAARQARAKALARQLGVAA (SEQ ID NO: 1) or functional equivalent thereof, and a pharmaceutically acceptable carrier, is effective to inhibit a kinase activity in the population of tumor cells and to reduce cancer cell proliferation, to reduce tumor size, to reduce tumor burden, to induce tumor cell death, to overcome tumor chemoresistance, to enhance tumor chemosensitivity, or a combination thereof.
