ERBB2 and breast cancer: reported a multiplexed detection system based on Raman‐label SERS (RL‐SERS) nanotags for simultaneous analysis of three critical breast cancer biomarkers (ER, PR, and HER2) in formalin‐fixed paraffin‐embedded tissue samples.[250] The system demonstrated excellent diagnostic capabilities, with sensitivity and specificity of 95% and 92% for single biomarker detection, 88% and 85% for dual detection, and 75% and 67% for triple detection.