A Study Without a Protocol Number. Documentation Filed in the Registry Under Number 01/19/1438. Date: 08.04.2019.

The research was conducted as a prospective controlled clinical experimental study in the period from 2019-2022. in patients who were treated at the Gynecology and Obstetrics Clinic in Clinical Center Kragujevac. Sections of tissue deriving from the exploratory curettage and operative procedure were taken after obtaining informed consent of participants with the declaration of Helsinki and recommendations of the World Health Organization for experiments on human material and after getting approval of the Ethics Committee.

Participants are divided into two groups. Investigators stored the sample (endometrial tissue) in liquid nitrogen under adequate conditions at the Kragujevac Clinical Center, department for Gynecology and Obstetrics and examined the expression of the COPB2 and Bcl-2 gene in endometrial tissue cells of these two groups of patients. In order to examine the relative expression of the gene for the COPB2 subunit and Bcl-2, investigators sampled endometrial tissue from patients with endometrial cancer - experimental group and from patients without cancer - control group. All participants of the experimental group had initial stages of cancer, without the existence of metastases at the time of taking the sample for the study. Gene expression was performed using the Polymerase Chain Reaction method at the Faculty of Science and Mathematics in Kragujevac.