Despite the different basal proliferation rates in the glioma cell lines investigated (the average percentage of cells at the G2/M phase of mitosis was 19 ± 0.64% of the total number of cells for U87, 27 ± 0.25% for A172 and 17 ± 1.76% for 965 cells), a 7–10-day treatment with gp120 resulted in an increase in the percentage of cells at the G2/M phase to 20.6 ± 0.51%, 28.5 ± 0.32 and 18.8 ± 1.6, respectively (n = 4). The gene discussed is ITIH4; the disease is central nervous system cancer.