Previous studies have reported comparable abnormal expression of EAOC-related genes, such as mismatch repair gene human mutL homolog 1 (hLMH1) and runt-related transcription factor3 (RUNX3), between EAOC and non-endometriosis-associated primary ovarian cancer (non-EAOC) groups [10, 11], giving rise to the speculation that all clear cell and endometrioid carcinomas of the ovary originate from malignant transformation of endometriosis. This evidence concerns the gene RUNX3 and endometriosis.