PAX8 and neoplasm: Immunohistochemical staining revealed that the late‐stage tumor (IP‐engrafted) was positive for PAX8 (FT epithelial marker),[33] TP53 (HGSOC marker),[36] WT1 (HGSOC marker),[37] and STMN1 (tumor progression),[49] confirming the tumor's mFT origin and metastatic potential (Figure 4C).