News Health & Medicine An overlooked organ may help the ovary function New findings in mice reveal that the newly rediscovered rete ovarii may communicate with the ovary The rete ovarii (in red) extends from the ovary, curving around the organ like a horseshoe. D. Anbarci et al/eLife 2025 By Meghan Willcoxon 1 hour ago When an expansive curlicue of tissue sitting below the ovaries was discovered more than a century ago, it was dismissed as useless and erased from biology textbooks. Biologists now are taking a new look at the structure and its potential role. The rete ovarii seems to communicate with the ovary by directing a flow of protein-packed fluids through its long, tubular structure into the organ, researchers report March 19 in eLife. The results come amid recent reports suggesting that the “rediscovered” appendage may be responding to the body’s hormonal signals. While still a hypothesis, the finding indicates that this complex structure may play a role in fertility and ovarian maintenance. Sign up for our newsletter We summarize the week's scientific breakthroughs every Thursday.