VCAM1 and neoplasm: found that coating pH‐sensitive emtansine‐liposome with macrophage membranes (RAW 264.7) could efficiently enhance their cellular accumulation in the metastatic sites of 4T1 tumor.[31] Mechanically, α4 and β1 integrins overexpressed on RAW 264.7 cells could interact with vascular cell adhesion molecule‐1 (VCAM‐1) overexpressed on 4T1 cell membrane, and endow macrophage membrane with inherent homing capability to metastatic 4T1 tumor.