PROX1 and carcinoma: Subsequently, the E#4 was defined as lymphatic endothelial (LEC) cells by the marker genes (LEC) (e.g., PDPN and PROX1), and E#1 was defined as carcinoma‐associated fibroblasts derived endothelial cells (CAFsEc) (e.g., S100A4) (Figure 1f,g).