To demonstrate the infection of BMMΦ and neonatal cardiomyocytes, these were adhered to glass coverslips and infected for 24 h with T. cruzi trypomastigotes of the QRO (more virulent) or CI2 (less virulent) isolates at a parasite/cell ratio of 2:1 and afterward were stimulated with TNF-α + IFN-γ or IL-4 for 48 h. This evidence concerns the gene IFNG and infection.