SLC34A2 and ovarian neoplasm: Interestingly, when a clinical upifitamab [36] scFv (Fig. 9A) against a type-2 sodium-dependent phosphate transporter named SLC34A2 (NaPi2b), known to be highly elevated in ovarian tumors [37] was tested, almost undetectable surface expression of NaPi2b on HeyA8 cells was observed as compared to OVCAR3 (Fig. 9B).