Infection of macrophages with L. major was found to enhance PKCδ/ζ/λ–dependent activation of ERK1/2 phosphorylation and Leishmania growth, but impair the functions of PKCα/β/ε responsible for p38MAPK phosphorylation and parasite killing, thus defining differential roles for PKC isoforms in immune homeostasis. The gene discussed is MAPK3; the disease is infection.