Consistent with increased activation of endothelial cells in our scRNAseq data, we found that NEC vascular endothelial cells up-regulated signaling to leukocytes via integrin receptors and cytokines including: macrophages via VCAM1-ITGB1 and IL6-F3 (Fig 6B), dendritic cells via VCAM1-ITGB1/ITGB7, and IL6-IL6ST (Fig 6C), and naïve T cells via MADCAM1-ITGB7, VCAM1-ITGB1/ITGB7/ITGB2/ITGA4, and IL6-IL6R/IL6ST (Fig 6D). Here, MADCAM1 is linked to necrotizing enterocolitis.