EGFR and cancer: Ultrasensitive measurement of protein was achieved using anti-epidermal growth factor receptors (anti-EGFR) antibody conjugated SERS nanotag (Figure 8) and the simultaneous detection of hepatocellular carcinoma biomarkers-alpha fetoprotein and alpha-1-antitrypsin secreted in the supernatant from the Hep3b cancer cell line was demonstrated [54].