Using scRNA-seq on tumor tissues from 12 treatment-naïve GBC patients (GBC1–12) and benign gallbladder tissues from six chronic cholecystitis patients (CC1–6), the authors isolated 8897 endothelial cells (endothelial markers: CD34, PECAM1, VWF) and subclustered them into eight endothelial subtypes. The gene discussed is CD34; the disease is neoplasm.