POU3F3 and squamous cell carcinoma: Tong et al. (2015) highlighted the diagnostic potential of plasma POU class 3 homeobox 3 (POU3F3) in ESCC (AUC 0.842; p < 0.001; sensitivity 72.8%; specificity 89.4%). When combined with Squamous Cell Carcinoma Antigen (SCCA), the diagnostic performance significantly improved, yielding an AUC of 0.926, sensitivity of 85.7%, and specificity of 81.4%. Notably, the combined detection of POU3F3 and SCCA effectively identified 80.8% of early ESCC cases (Tong et al., 2015).