CYCS and infection: Of particular interest, CL7 EVs were also deficient in surface protein amastin and CL8 EVs were deficient in cytochrome C. Cytochrome C is an important oxidase that allows Leishmania to adapt to human macrophage environment and amastin is a classical Leishmania surface virulence factor, important for parasite survival in the sandfly vector as well as infection (Cardenas et al., 2015; de Paiva et al., 2015).