To determine how the TME evolves over the extended static culture period, harvested TPCS were H&E-stained and immunohistochemically analyzed for Ki-67, αSMA, VCAM-1, CD3, F4/80 and CD79A to assess tumor cell proliferation, stromal cell activation, endothelial cell proliferation, and immune cell viability, respectively (Figure 5E). The gene discussed is MKI67; the disease is neoplasm.