FZD2 and oral cavity squamous cell carcinoma: FZD2 showed promise as a diagnostic biomarker in BLCA, BRCA, CHOL, ESCA, HNSC, oral squamous cell carcinoma (OSCC), READ, and STAD, with AUCs of 0.829, 0.808, 0.971, 0.921, 0.955, 0.950, 0.717, and 0.858, respectively (Figures 3D–K).