The law of stage-by-stage development of human tumors, derived from the results of ploidometric studies.

The ploidy of 56,000 epithelial cell nuclei was studied at different stages of carcinogenesis by Imager-CG computer image analyzer. The linear relationship between carcinogenesis stages and quantitative parameters (indexes of mean ploidy of cell nuclei) at a certain stage was detected and mathematically described. A step-by-step increase of DNA content in cell nuclei by one unit of ploidy leads to emergence of new biological properties, measured by the number of units surpassing the normal cell nuclear ploidy values, which was called "the malignancy code".