During the flow cytometry analysis of activity of NF-κB in breast cancer cell lines incubated with tested compound, it was shown that pyrazolo[4,3-e]tetrazolo[1,5-b][1,2,4]triazine derivative (3b) leads to decreased number of cells with active NF-κB (Figure 5). The gene discussed is NFKB1; the disease is breast cancer.