Since chicks in the protected biofactors and antioxidant (P(BF + AO)) feed additive-fed hen group had a 32.6 percent reduction of SE, the increase in IL-16 levels could be because the immune system is having to work harder to fight off infection which could also be linked to why we are seeing an increase in our ST group (Swaggerty et al., 2023). The gene discussed is IL16; the disease is infection.