CD274 and colitis: Healthy mice and colitis mice were treated with PD-L1-Fc/Cy5-Oxi-αCD nanoparticles by intraperitoneal injection for 8 h, and fluorescence imaging of colon cryosections revealed notably accumulated fluorescence in the mucous lamina propria of the colon from colitis mice, not in that from healthy mice (Supplementary Fig. 7).