“…Moreover, reduced border regulation and increased paracellular permeability increase the progression, proliferation, viability, migration, and invasion of tumor cells by allowing the passage of necessary growth factors and nutrients. Claudin expression patterns can also indicate tumor type as the distinct fashion in which the Claudin proteins aggregate in cells depends on the cell type and location [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ] ( Figure 3 ). Claudin-4 is a marker of cellular differentiation and an indicator for phenotypic expression of the epithelia and thus a plausible target for therapeutic intervention for several cancers and their precursors.…”