Naphthol AS-MX phosphate (NASTRp) is a small-molecule inhibitor targeting the CREB (cyclic adenosine monophosphate response element-binding protein)-CBP (CREB-binding protein) transcription factor complex. It exhibits antitumor activity against lung cancer cells by inhibiting tumor cell proliferation (IC50=3.701 μmol/L), colony formation, and anchorage-independent growth in soft agar. This compound is valuable for studying KRAS-mutant lung cancer, particularly in cases of chemotherapy resistance and poor prognosis.