Figure 1.

Complete loss of ARID1A/BAF250a protein expression in poorly differentiated PDAC. A, BAF250a staining was completely negative in this case, in that the nucleus has blue staining; original magnification ×40. B, Negative immunohistochemical staining of BAF250a in poorly differentiated PDAC; original magnification ×100. C-D, Poorly differentiated tumor cells had negative staining. Lymphocytes, endothelial cells, and stromal cells with nuclear BAF250a expression served as internal positive controls; original magnification ×400. ARID1A indicates AT-rich interactive domain 1A. PDAC, pancreatic ductal adenocarcinoma.