Using co-immunoprecipitation assays, we revealed that TFPI-2 does not simultaneously interact with actinin-4 and myosin-9 in the cytoplasm of breast cancer cells, since neither myosin-9 is detected in the precipitates of actinin-4 antibody, nor actinin-4 in the precipitates of mysosin-9 antibody. The gene discussed is MYH9; the disease is breast cancer.