Inducing roles of BP7 in a chicken immunization model. Chickens were immunized twice with BP7 and an AIV H9N2 antigen. A HI antibody levels. B IL-4 and IFN-γ cytokine production. C Lymphocyte viability. Data represent the mean ± standard deviation (s.d.). Significant differences between groups were determined using Student’s t-test, where p < 0.05 is indicated by an asterisk (*).