KRT18 and endometriosis: In our study, the protein expression of the CK-18-positive area and the mRNA expression of CK-18 consistently increased in the endometriosis group compared with the control group in the peritoneum, as depicted in Figure 5B and Figure 6B. However, in the other endometriosis model where uterine fragments were dispersed within the peritoneal cavity, the investigation revealed that the protein expression in the CK-18-positive area remained unaltered, while there was an increase in the mRNA expression of CK-18 between the endometriosis and control groups (Figure 4B and Figure 6A).