CD4 and cancer: The ratio of circulating CD8+ Т-cells to CD4+CD25+FoxP3+ regulatory lymphocytes (CD3+CD8+/Treg, Fig.3) was lowered in patients relative to the controls (p = 0.002 for the total patient group) as a result of increasing frequency of regulatory cells and declining numbers of CD3+CD8+ cells that could be seen upon invasive cancer formation (at the same time, there was no statistically significant difference in the number of CD3+CD4+ Т-cells between the patient and the control groups).