Tumor is a cell population in which cells are born age and die. Applying the stream metaphor to tumor, tumor size is its tolerance, newborn cells are its upper stream, and dying cells, its lower stream. Suppose that cancer consists only of the tumor. Treatment objective would be to lower tumor tolerance, which may be achieved either by diminishing cell birth or increasing cell death, or both. Chemotherapy generally reduces the first. M- and S-poisons inhibit birth, while cells continue aging until their death and tumor shrinks.

Chemotherapy depends on WOB assistance, since only WOB eliminates tumor cells. Initially it cooperates and tumor shrinks, yet soon tumor regains its size, and becomes resistant to chemotherapy. While medicine blames resistance genes for its failure, it is WOB that refuses to cooperate, since chemotherapy was administered against its principles.