In addition, in the tumors established from the HT-29SUN cells, the effect of sunitinib treatment on microvessel density was similar to the effect in the HT-29PAR tumors, while the effect on the percentage of proliferating (Ki-67 positive) tumor cells was decreased in the sensitive, but not in the resistant HT-29SUN xenografts (Figure 3). Here, MKI67 is linked to neoplasm.