Here we show, using wide-field macroscopic and microscopic TD fluorescence imaging of a PD-L1 antibody tagged to IRDye 800CW (αPDL1–800), that the tumor FLT of αPDL1–800 is significantly longer compared to the nonspecifically accumulated αPDL1–800 in the TME and in surrounding normal tissue. This evidence concerns the gene CD274 and neoplasm.