Authors associated this outcome with the development of a Delayed-Type Hypersensitivity (DTH) reaction and with IFN-γ production, the latter acting as the hallmark cytokine associated with protection against Leishmania. Soon after, PpSP15 was identified in P. papatasi saliva, and mice immunized with the corresponding DNA plasmid were protected against a challenge infection with L. major (33). The gene discussed is IFNG; the disease is infection.