L1CAM and neoplasm: We also observed that the VTT tissue with vessel wall invasion showed strong positive staining for L1CAM (Fig. 5G), the L1CAMhigh/CXCR2high RCCs subgroup was more prone to perivascular localization in the VTT, promoted VTT adherence to the vascular wall, and deployed the perivascular tumor niche (Fig. 5H).