PECAM1 and neoplasm: However, the perfused labeling of Lectin‐Alexa 633 in the precursor lesions partially overlapped with that of CD31‐FITC, the overlapping decreased from the precursor lesions to tumor regions, and some microvessels labeled with Lectin‐Alexa 633 were absent with CD31‐FITC labeling and vice versa (Figure 3C,D).