Children with moderate-to-heavy ascariasis had lower IFN-γ mean values (37.6 [15.7–90.0] pg/mL) compared with those having no or light infections (131.5 [98.4–175.8] pg/mL and 214.4 [99.0–464.4] pg/mL, resp). This evidence concerns the gene IFNG and ascariasis.