{"paper_id":"bfcd439d-0d30-4980-8481-e3a7e6ea25b7","body_text":"To the Editor:\nI read with interest the recent article by Nakayama et al. describing focal p53 expression in endometriotic lesions (). I have occasionally observed endogenous biotin expression in endometriotic lesions (personal observation) in a pattern very similar to that illustrated in Figure 2 of the article (isolated cells with intense nuclear staining). Although the Materials and Methods section did not mention negative controls, I presume these were done. Negative controls should be reviewed to rule out the possibility of false positive staining due to endogenous biotin.\nKhush Mittal, M.D.REFERENCES\n- 1. Nakayama K, Toki T, Zhai YL, et al. Demonstration of focal p53 expression without genetic alterations in endometriotic lesions. Int J Gynecol Pathol 2001; 20: 227–31.","source_license":"CC0","license_restricted":false}