For stable infections of LL-5 cells, we found that Wolbachia had no effect on the expression levels of any of the genes tested in comparison with the uninfected cells, whereas for Lulo, which acquired higher Wolbachia density, the presence of the endosymbiont decreased the expression of some genes from the main immune system pathways, such as Cactus, Caspar, PIAS, PPO and TEP1. Caspar downregulation suggests that upon Wolbachia transinfection, this immune pathway may be activated in Lulo cells. The gene discussed is PPOX; the disease is infection.