Tumors treated with nanoconjugate drugs showed significantly less PCNA and Ki67 immunoreaction (< 20% of the total area occupied by tumor cells) compared with those treated with the free form of the drugs (< 30%), but both forms induced significant decrease in the proliferative capacity of the tumor cells compared with untreated tumors (> 70% of the total area occupied by tumor cells) (Fig. 4a-j). This evidence concerns the gene PCNA and neoplasm.