Figure 9: Tissue samples from human patients exhibit variations in acini morphology along the metastatic cascade similar to the 3D cultures. In the nontumorigenic glands from a healthy patient shown in (a), integrin 𝛼 3 can be observed along the lateral surface of the epithelia, while integrin 𝛼 6 shows strong staining across the basal surface. Precancerous gland shown in (b) exhibits a clear reduction in the amount of integrin 𝛼 3 expression along the lateral membranes of the epithelia, while basal integrin 𝛼 6 expression remains strong. Noninvasive carcinoma gland shown in (c) could be easily identified by the loss of a proper hollow lumen and stratification of the epithelial layer. In these large regions of tissue, integrin 𝛼 3 is absent from cells in the interior of the gland; however, along with integrin 𝛼 6, there can be observed along the basal surfaces of cells in contact with the basal lamina. Invasive carcinoma gland shown in (d) includes cords or clusters of cells exhibiting faint labeling of both proteins distributed along the cell membrane compared to background and control tissue. Scale bars represent 20 μm in (a) and (c), and 10 μm in (b) and (d).