VF transcript expression did not differ by source of cultured isolate (ATCC® versus clinical) for all baseline pure Leishmania cultures (pre-macrophage infection) for the following: gp63 (p = 0.74), cpb (p = 0.79), mpi (p = 0.79), hsp23 (p = 0.74), hsp70 (p = 0.68), hsp90 (p = 0.79), hsp100 (p = 0.57), and pooled (p = 0.86) analyses (Additional file 2: Figure S5). This evidence concerns the gene MPI and infection.