FOS and infection: Specifically, our data show that exposure of PHCM to T. cruzi during a two hour period, time to capture the early events occurring during infection, leads to a significant increase in the transcript levels of JunB, FOS, EGR1, EGR3, and SNAI1; a group of TFs and transcription regulatory genes that have the potential to tilt PHCM towards a profibrotic response.