Some studies claim that re-examination for histopathologic CE following first-line doxycycline treatment is clinically insignificant in improving reproductive outcomes in infertile women undergoing assisted reproductive technology treatment [92]; however, a growing number of studies demonstrate that antibiotic treatment may improve the reproductive outcomes of infertile women with a history of RIF in subsequent IVF-ET cycles only if the cure of histopathologic CE is confirmed in the endometrial biopsy/IHC-CD138 afterward [20]. Here, SDC1 is linked to cholesteryl ester measurement.