Quantitative in vivo imaging of NIR800-EGF uptake reflects the relative EGFR immunoreactivity in colorectal cancer xenografts. A, representative in vivo fluorescence images of SW620 (EGFR-negative), HCT-116 (EGFR-moderate), and DiFi (EGFR-high) tumor-bearing mice 24 h post-administration of NIR800-EGF. T, tumor; K, kidney. B, relative in vivo uptake of NIR800-EGF in SW620, HCT-116, and DiFi tumors. C, total EGFR immunoreactivity in tumor specimens from SW620, HCT-116, and DiFi xenografts shown in A and B.