In vitro treatment of BRL-3A cells with exosomes from hypertrophic liver tissue at 6, 24, and 48 h after PVL resulted in significant upregulation of JAG1, Notch1, NICD, YAP, Sox9, Hes1, and Cyclin D1 compared to Sham-E group (Fig. 2G), and the corresponding gene expression also significantly increased (Supplementary Fig. 3). Here, HES1 is linked to periventricular leukomalacia.