SPP1 and cervical cancer: Recently, surface-enhanced Raman spectroscopy (SERS) has also been applied to the detection of cervical cancer biomarkers in serum, such as squamous cell carcinoma antigen (SCCA), osteopontin (OPN), cancer antigen 125 (CA125), and surviving [73,74,75] and B7 homolog 6 (B7-H6) protein [76].