Figure 2.

Immunohistochemistry of deep and incisional endometriosis samples showing (A) loss of ARID1A in epithelial endometriosis cells and (B) matching haematoxylin and eosin staining from deep endometriosis patient 47. Similarly, we observed both deep and incisional endometriosis with heterogeneous expression of PTEN. For example, incisional endometriosis patient 17 (C) shows intermediate PTEN expression in some regions of glandular epithelium, while (D) loss of PTEN expression was apparent in other regions. In both the context of ARID1A and PTEN immunohistochemistry, the endometriosis stromal compartment (and surrounding normal tissues) provides a clear, block-specific, positive control with strong expression visible for both proteins, respectively.