MKI67 and neoplasm: Using fluorescence intensity as a readout for cetuximab-IRDye800CW accumulation within the tissues, the MFI was correlated with biological characteristics of the tumor that might also influence antibody (peri-)tumoral distribution and binding into the tumor including cytokeratin (tumor density), EGFR expression, Factor VIII (vascular density) and Ki67 (proliferation) for each dose group (Table 1).