TGFB1 and infection: Upon pathogen infection, the nematode can mount protective responses by triggering evolutionarily conserved immune signaling pathways, including the p38/PMK-1 mitogen-activated protein kinase (MAPK) pathways, the DAF-2/insulin-like receptor pathway, the DBL-1/transforming growth factor β (TGF-β) pathway, the unfolded protein responses (UPRs), and programmed cell death (13).