Although the potency of theasinensin A monotherapy was not completely satisfactory, combination with an anti-EGFR antibody significantly reduced the IC50 value obtained against NSCLC cells overexpressing EGFR by inducing degradation of surface EGFR expression and leading to tumor shrinkage in NCI-H441-xenograft-bearing mice. This evidence concerns the gene EGFR and non-small cell lung carcinoma.