CD274 and neoplasm: This process was visualized by using triple oblique NIR‐II light‐sheet microscopy to delineate the 3D spatial distribution of PD‐L1 (labeled by anti‐PD‐L1 Er NPs), PD‐1 (labeled by anti‐PD‐1 CSQD), and the blood vascular system (labeled by p‐FE) of the tumor (Figure 10C).[208] The whole process of anti‐PD‐L1 tumor immunotherapy can thus be visualized in vivo through the NIR‐II window.