Staining for the proliferation marker Ki67 revealed that tumor cell proliferation in tumors treated with 10 μg PrAg-PCIS toxin or 5 μg PrAg-PCIS toxin was significantly reduced by 3.3-fold and 2.3-fold respectively, relative to vehicle treatment, and was associated only with the remaining viable areas of the tumors (Figures 8B, 8F). This evidence concerns the gene MKI67 and neoplasm.