PRL and Infertility: During the analysis of the expression of the major genetic markers of decidualization, the hormone prolactin (PRL), the progesterone receptor gene (PCR), the estrogen receptor (ESR), insulin-like growth factor binding protein 1 (IGFBP) and forkhead box protein O1 (FOXO1), we revealed changes in PRL, PCR, ESR, IGFBP, FOXO1 expression in time manner and difference in the groups (healthy vs. infertile).