TNF and endometritis: The RT-qPCR analysis of the inflammatory cytokines (IL-1β, IL-6, TNF-α) in the two groups demonstrated that the mRNA expression levels of IL-1β, IL-6, and TNF-α were significantly upregulated in the endometritis group compared to the healthy group (* p < 0.05; ** p < 0.01) (Figure 1B–D).