Furthermore, a randomized, double‐blind, placebo‐controlled clinical trial evaluated the effects of DDP4 inhibitors in regulating the endometrial decidual cells in recurrent miscarriage; DDP4 inhibitors mainly increase CXCL12 bioactivity, which at least partly depends on recruitment and engraftment of BMDCs and their subsequent differentiation into nonhematopoietic endometrial lineage, thereby increasing the mid‐luteal phase endometrial CFUs, endometrial thickness, and 12‐month pregnancy outcomes in women with a history of recurrent miscarriage (Tewary et al., 2020). This evidence concerns the gene CXCL12 and spontaneous abortion.