Plasminogen is expressed in cytoplasm and can be activated by staphylokinases of Staphylococcus aureus following inhibition of cell complement activation and degradation of immune proteins like IgG and C3b (Rooijakkers et al., 2005), so upregulation of the two proteins may exacerbate pathogen infections like Staphylococcus aureus and Escherichia coli. Here, C3 is linked to infection.