In 2008, a topological model of NaPi2b consisting of at least eight potential transmembrane domains (TMD), five putative intracellular domains, and four putative extracellular loops, with both N- and C-terminal regions probably facing the cytoplasm in ovarian cancer cells was computationally predicted (Yin et al., 2008). The gene discussed is SLC34A2; the disease is ovarian cancer.