WFDC2, one of the most extensively studied members, displays a functional dichotomy: it serves as a diagnostic biomarker in lung, ovarian, and prostate cancers [11, 15, 32, 33], with clinical utility as a serum marker for ovarian cancer [34], yet paradoxically suppresses prostate cancer metastasis by inhibiting EGFR-mediated cell migration [15]. The gene discussed is WFDC2; the disease is prostate cancer.