CHI3L1 and endometriosis: In addition, there are also the limitations of Chi3l1 as a biomarker due to the insufficient specificity and sensitivity, different inclusion criteria in the study, and differences in expression levels among individuals, etc. Thus, combined diagnosis of multiple biomarkers (e.g., noninvasive diagnosis of the endometriosis stage with a triple combination panel of Chi3l1/IL-37/CA125) could be a promising strategy for improving the accuracy of disease diagnosis.