Further experiments using the human epithelial cell line A549 verified synergistically elevated IL-6 mRNA levels at different time points upon super-infection with IV H1N1(M), H7N7, FluB, H3N2 or H1N1 and the S. aureus strains 6850, SH1000 or MRSA USA300 compared to single pathogen-infected cells (Fig. 2). The gene discussed is IL6; the disease is infection.