Among the resulting DNA-MBD1-AuNP assemblies (DMAs), DMA_21mCG with the highest aspect ratio of rod-shaped assembly of AuNPs showed the highest-level PT and PA activities and the best performance in targeting EGFR-expressing cancer cells, suggesting that DMA_21mCG holds a promising potential as a cancer theragnostic agent. This evidence concerns the gene EGFR and cancer.