Thus, we aimed to ascertain the relative abundance of known VF RNA transcripts, including hsp23, hsp70, hsp90, hsp100, cpb, zinc metalloproteinase GP63 (gp63), and mannose phosphate isomerase (mpi), previously evaluated in Old World strains and for which sequences were readily available through the National Center for Biotechnology Information (NCBI) database, in pure cultures and a macrophage model of infection with several species of the Leishmania Viannia subgenus, a group around which few such data exist. Here, MPI is linked to infection.