ARL15 and neoplasm: Endothelial cell (EC) is a major component with vast heterogeneity of tumor microenvironment by promoting tumor growth and metastasis.57, 58, 59 To further explore the differences of ECs between CSCC and CAde, 6040 ECs were divided into three vascular endothelial cells (vEC) subclusters (vEC-cluster 1: ADAMTSL1 and MYRIP, vEC-cluster 2: PODXL and ARL15, vEC-cluster 3: HPSE2 and KCNIP4) andone LEC subcluster (CCL21 and PROX1) based on marker gene expression profiles (Supplementary Figure S5a–c).